The core cannot store an excessive amount of heat without upsetting its delicate thermal balance. Your ability to cope with heat, both at rest and during work, depends upon the stability of your core body temperature. If the core temperature can be stabilized at a high of 100oF (38oC), you will probably be safe.Sep 12, 2016 · The lower the AQI, the cleaner the air is. However, if you are outside when the AQI is over 100, it’s about the same as breathing in exhaust from a car all day! Things that cause poor air quality are forest fires and cities with lots of car traffic. If the AQI is higher than 100 you shouldn’t spend too much time outside. Jul 3, 2019 · Dear Tom, Parade Magazine’s Marilyn Savant says air temperature is the same in the sun as in the shade, but placing a thermometer in the sun heats up the thermometer. Body temperature is affected by outside temperature, but not in a way you think. The body has a very sensitive thermometer called the hypothalamus, which can detect the difference between one’s warm and cold environment. If the environment is too cold, it will make your body shiver to produce heat, and if it’s too hot, you’ll sweat to ...Aug 20, 2023 · When there's low relative humidity, we can feel much cooler than the actual temperature because our sweat evaporates easily, cooling us off. For example, if the air temperature is 75 degrees Fahrenheit (24 degrees Celsius) and the relative humidity is zero percent, the air temperature feels like 69 degrees F (21 C) to our bodies. If the air ... Solar radiation can dramatically change the temperature of an object that it hits, heating it far above the actual air temperature. Jack Williams, former weather editor for "USA Today," stood outside in air that measured in the 20s Fahrenheit in the shade, but a thermometer in the sun behind him registered 80 degrees Fahrenheit.Io (/ ˈ aɪ. oʊ /), or Jupiter I, is the innermost and third-largest of the four Galilean moons of the planet Jupiter.Slightly larger than Earth’s moon, Io is the fourth-largest moon in the Solar System, has the highest density of any moon, the strongest surface gravity of any moon, and the lowest amount of water (by atomic ratio) of any known astronomical object in the Solar System.The lower the AQI, the cleaner the air is. However, if you are outside when the AQI is over 100, it’s about the same as breathing in exhaust from a car all day! Things that cause poor air quality are forest fires and cities with lots of car traffic. If the AQI is higher than 100 you shouldn’t spend too much time outside.According to a 1958 NASA report, people can live indefinitely in environments that range between roughly 40 degrees F and 95 degrees F (4 and 35 degrees C), if the latter temperature occurs at no ...Simply rearranging the RH equation, U = (RH) x (U s) = (0.5) x (7.6 g/kg) = 3.8 g/kg. Step 3. Use the table of saturation mixing ratios to find the dew point temperature. Locate U = 3.8 g/kg in the right hand column. The corresponding entry in the left hand column is the dew point temperature, T d = 0°C. The Weather Channel and weather.com provide a national and local weather forecast for cities, as well as weather radar, report and hurricane coverage Apr 29, 2022 · Water-based exterior paint requires certain conditions to cure—or fully harden—properly. If it doesn’t do that, you might be repainting your home’s exterior sooner than you planned. “It ... The ideal body temperature in adults is around 98.6°F (37°C), but this varies based on age, physical activity, and health. Body temperature also changes throughout the day. A temperature of ...Solar radiation can dramatically change the temperature of an object that it hits, heating it far above the actual air temperature. Jack Williams, former weather editor for "USA Today," stood outside in air that measured in the 20s Fahrenheit in the shade, but a thermometer in the sun behind him registered 80 degrees Fahrenheit.Current weather in Orlando, FL. Check current conditions in Orlando, FL with radar, hourly, and more.Stellenbosch, South Africa. Stellenbosch’s annual weather data make it look like a microclimate supermodel: 71 (average annual high) by 50 (average annual low) by 36 (annual average rain in ...The Missouri Department of Natural Resources assists in finding funding mechanisms for energy improvements, educates Missourians and promotes efficient use of energy resources for economic growth, a healthy environment, and a better Missouri for future generations. This includes efforts to bring innovative energy solutions to market ...Enter a temperature that you would like and choose your units: What the temperature feels like to your body: Fahrenheit Celsius ° F: Enter your relative humidity: % temperature is 10°F, when this air is brought into the home and heated to 70°F, the indoor RH drops to 6%. To put this in perspective, the Sahara Desert averages 23% humidity! The chart below further illustrates what happens to air when it’s heated. Relative Humidity Defined OUTDOOR-INDOOR RELATIVE HUMIDITY CONVERSION CHART. age inside temperature falls with outsIde temperature. In this house, the average inside temperature falls about 1°C for every 10 °C fall in outside temperature (slope = +0.1). There is a simpie explanation for this phenomenon: the simulatlon assumed that the house's thermostat was set 21°C during the day and 13°CThe 1-5% range places water vapor as the third most common gas (which alters the other percentages accordingly). Water content varies according to air temperature. Dry air is denser than humid air. However, sometimes humid air contains actual water droplets, which can make it more dense than humid air that only contains water vapor.According to this method, one can determine how much moist a moisturizer must spray. In practise, one should adopt a worst-case scenario. For example, in winter at an outside temperature of -10 °C and a relative humidity of 30%, one wishes to create a satisfactory indoor climate (such as 20 °C and a minimal relative humidity of 40%).What is the lowest temperature that can theoretically be obtained from the air coming off the cooling pads if the outside air has a 90. o. F dry bulb temperature and 35 percent relative humidity? Answer: Locate the intersection of the 90. o. F dry bulb temperature line and the 35 percent relative humidity line (which is not shown on the chart, butHeat pumps quit working efficiently as they used to when the outside temperature reaches about 40 degrees Fahrenheit, and you can say that anything below the range of 25 to 30 degrees is a temperature a heat pump is not effective. Therefore, you can count on a conventional heat pump as a solution for your HVAC requirements as long as the ...What was the temperature on Thursday? Degrees Fahrenheit. What is the current temperature if the temperature is 12 degrees Fahrenheit and changes by -26 degrees Fahrenheit? Temperature rise 2. Find the temperature after a rise of 5°C from -20°C. Yesterday. Yesterday the temperature was 24.5°C. Today, the temperature has dropped by 5°C. Jul 1, 2015 · MAT = (Proportion of OA x OAT) + (Proportion of RA x RAT) MAT = (.10 x 45) + (.90 x 70) “So there it is”, said Rick, “Close the fresh air damper slowly until the MAT (Mixed Air Temperature) measures 67.5 degrees and you now are set at 10% Outdoor Air.”. As you might have guessed, the greater the difference between the OAT and the RAT ... Heat index is often referred to as humiture, and is similar to wind chill in its attempt to measure the perceived rather than the actual temperature. For example, an air temperature of 83°F with a relative humidity of 70% would result in an estimated 88°F perceived temperature. This difference in perceived and actual temperature is the result ...On average, the temperature on Mars is about minus 80 degrees F (minus 60 degrees Celsius) according to NASA. In winter, near the poles, temperatures can get down to minus 195 degrees F (minus 125 ...The report, published by The Heartland Institute, was compiled via satellite and in-person survey visits to NOAA weather stations that contribute to the “official” land temperature data in the United States. The research shows that 96% of these stations are corrupted by localized effects of urbanization – producing heat-bias because of ...(1) The zeroth law of thermodynamics allows this definition to be used to measure the absolute or thermodynamic temperature of an arbitrary body of interest, by making the other heat reservoir have the same temperature as the body of interest. Kelvin's original work postulating absolute temperature was published in 1848. It was based on the work of Carnot, before the formulation of the first ...If the air temperature is 100 degrees Fahrenheit with 55% humidity, for example, the heat index is 124 degrees. You feel much hotter because your sweat won't evaporate as easily. Conversely, if the heat index is lower—say 15%—that same 100 degrees actually would feel like 96. You can view the heat index chart at the National Weather Service ...Earth's climate is largely determined by the planet's energy budget, i.e., the balance of incoming and outgoing radiation. It is measured by satellites and shown in W/m 2. The imbalance (or rate of global heating; shown in figure as the "net absorbed" amount) grew from +0.6 W/m 2 (2009 est. [1]) to above +1.0 W/m 2 in 2019 [2].The American Society of Heating Refrigeration, Air Conditioning Engineers recommends keeping your home's relative humidity between 40-60 percent. Use our relative humidity charts to find the proper humidity level in your house. Outside of this range, your air and your body are more susceptible to airborne pollutants such as allergens, mold ... This is sometimes referred to as a unit of standard atmospheres (atm). Total atmospheric mass is 5.1480×10 18 kg (1.135×10 19 lb), [40] about 2.5% less than would be inferred from the average sea level pressure and Earth's area of 51007.2 megahectares, this portion being displaced by Earth's mountainous terrain.The animation on the right shows the change in global surface temperatures. Dark blue shows areas cooler than average. Dark red shows areas warmer than average. Short-term variations are smoothed out using a 5-year running average to make trends more visible in this map. The data shown are the latest available, updated annually.(1) The zeroth law of thermodynamics allows this definition to be used to measure the absolute or thermodynamic temperature of an arbitrary body of interest, by making the other heat reservoir have the same temperature as the body of interest. Kelvin's original work postulating absolute temperature was published in 1848. It was based on the work of Carnot, before the formulation of the first ... The American Society of Heating Refrigeration, Air Conditioning Engineers recommends keeping your home's relative humidity between 40-60 percent. Use our relative humidity charts to find the proper humidity level in your house. Outside of this range, your air and your body are more susceptible to airborne pollutants such as allergens, mold ... (1) The zeroth law of thermodynamics allows this definition to be used to measure the absolute or thermodynamic temperature of an arbitrary body of interest, by making the other heat reservoir have the same temperature as the body of interest. Kelvin's original work postulating absolute temperature was published in 1848. It was based on the work of Carnot, before the formulation of the first ...Dear Tom, Parade Magazine’s Marilyn Savant says air temperature is the same in the sun as in the shade, but placing a thermometer in the sun heats up the thermometer.Water-based exterior paint requires certain conditions to cure—or fully harden—properly. If it doesn’t do that, you might be repainting your home’s exterior sooner than you planned. “It ...Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. [2] Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depends on the temperature and pressure of the system of interest.Sep 12, 2016 · The lower the AQI, the cleaner the air is. However, if you are outside when the AQI is over 100, it’s about the same as breathing in exhaust from a car all day! Things that cause poor air quality are forest fires and cities with lots of car traffic. If the AQI is higher than 100 you shouldn’t spend too much time outside. Absolute humidity (expressed as grams of water vapor per cubic meter volume of air) is a measure of the actual amount of water vapor (moisture) in the air, regardless of the air's temperature. The higher the amount of water vapor, the higher the absolute humidity. For example, a maximum of about 30 grams of water vapor can exist in a cubic ... Jun 9, 2016 · If your thermostat is normally at 72 degrees, try gradually lowering it to 68 degrees. Studies have shown that there is little difference in most people’s comfort between these two temperatures, and every degree you lower your thermostat saves you 1 – 3% on your electric bill. Remember that clothes matter as well: a thick sweater is the ... Based on the annual report from NOAA’s Global Monitoring Lab, global average atmospheric carbon dioxide was 417.06 parts per million (“ppm” for short) in 2022, setting a new record high. The increase between 2021 and 2022 was 2.13 ppm—the 11 th year in a row where the amount of carbon dioxide in the atmosphere increased by more than 2 ...Solar radiation can dramatically change the temperature of an object that it hits, heating it far above the actual air temperature. Jack Williams, former weather editor for "USA Today," stood outside in air that measured in the 20s Fahrenheit in the shade, but a thermometer in the sun behind him registered 80 degrees Fahrenheit.May 4, 2021 · The latest 1991–2020 U.S. Climate Normals are an update to the Normals for the previous 3 decades, 1981-2010. NOAA’s Climate Normals are statistical calculations of weather observations — such as temperature, precipitation and snowfall — from approximately 15,000 federal weather stations across the United States and its territories. Jun 28, 2018 · On a 100-degree day, even if the windows are cracked, the temperature inside the car can soar to about 119 degrees in just ten minutes. And to 129 in just 20 minutes. NBC 5. Even on a mild day at ... (1) The zeroth law of thermodynamics allows this definition to be used to measure the absolute or thermodynamic temperature of an arbitrary body of interest, by making the other heat reservoir have the same temperature as the body of interest. Kelvin's original work postulating absolute temperature was published in 1848. It was based on the work of Carnot, before the formulation of the first ... EARTH MARS; Average Distance from Sun: 93 million miles: 142 million miles: Average Speed in Orbiting Sun: 18.5 miles per second: 14.5 miles per second: DiameterOutside of the TNZ exist the upper and lower critical tem-perature zones. When temperatures are in these zones the dog has to expend energy to maintain its body temperature. When this is no longer possible, hypo- or hyperthermia occurs. It is important to consider coat thickness and other specific breed This is sometimes referred to as a unit of standard atmospheres (atm). Total atmospheric mass is 5.1480×10 18 kg (1.135×10 19 lb), [40] about 2.5% less than would be inferred from the average sea level pressure and Earth's area of 51007.2 megahectares, this portion being displaced by Earth's mountainous terrain. Jul 21, 2023 · Since 1901, the average surface temperature across the contiguous 48 states has risen at an average rate of 0.17°F per decade (see Figure 1). Average temperatures have risen more quickly since the late 1970s (0.32 to 0.55°F per decade since 1979). Nine of the top 10 warmest years on record for the contiguous 48 states have occurred since 1998 ... Aug 20, 2023 · When there's low relative humidity, we can feel much cooler than the actual temperature because our sweat evaporates easily, cooling us off. For example, if the air temperature is 75 degrees Fahrenheit (24 degrees Celsius) and the relative humidity is zero percent, the air temperature feels like 69 degrees F (21 C) to our bodies. If the air ... According to NOAA's 2021 Annual Climate Report the combined land and ocean temperature has increased at an average rate of 0.14 degrees Fahrenheit ( 0.08 degrees Celsius) per decade since 1880; however, the average rate of increase since 1981 has been more than twice as fast: 0.32 °F (0.18 °C) per decade. The amount of future warming Earth ...Water-based exterior paint requires certain conditions to cure—or fully harden—properly. If it doesn’t do that, you might be repainting your home’s exterior sooner than you planned. “It ...The core cannot store an excessive amount of heat without upsetting its delicate thermal balance. Your ability to cope with heat, both at rest and during work, depends upon the stability of your core body temperature. If the core temperature can be stabilized at a high of 100oF (38oC), you will probably be safe.Nov 26, 2013 · Solar radiation can dramatically change the temperature of an object that it hits, heating it far above the actual air temperature. Jack Williams, former weather editor for "USA Today," stood outside in air that measured in the 20s Fahrenheit in the shade, but a thermometer in the sun behind him registered 80 degrees Fahrenheit. Absolute humidity (expressed as grams of water vapor per cubic meter volume of air) is a measure of the actual amount of water vapor (moisture) in the air, regardless of the air's temperature. The higher the amount of water vapor, the higher the absolute humidity. For example, a maximum of about 30 grams of water vapor can exist in a cubic ... 140-190. Aluminum reflective coated. Up to 68 degrees cooler than black roofs. 125-140. Unpainted metal. 138-145, but feels hotter to the touch than a black roof. Painted Metal (ex: BASF Cool Paint) 105-115 or up to 42% cooler than unpainted metal. The rooftop temperature results from two different properties.Earth's climate is largely determined by the planet's energy budget, i.e., the balance of incoming and outgoing radiation. It is measured by satellites and shown in W/m 2. The imbalance (or rate of global heating; shown in figure as the "net absorbed" amount) grew from +0.6 W/m 2 (2009 est. [1]) to above +1.0 W/m 2 in 2019 [2]. MAT = (Proportion of OA x OAT) + (Proportion of RA x RAT) MAT = (.10 x 45) + (.90 x 70) “So there it is”, said Rick, “Close the fresh air damper slowly until the MAT (Mixed Air Temperature) measures 67.5 degrees and you now are set at 10% Outdoor Air.”. As you might have guessed, the greater the difference between the OAT and the RAT ...Dec 5, 2017 · The outside air temperature will continue to be updated every second as long as the outside air temperature is the same or cooler than the previous reading. Once the new outside air temperature reading exceeds the previous temperature and the vehicle is traveling less than 18 mph (29 km/h), the displayed outside air temperature will remain at ... Earth's climate is largely determined by the planet's energy budget, i.e., the balance of incoming and outgoing radiation. It is measured by satellites and shown in W/m 2. The imbalance (or rate of global heating; shown in figure as the "net absorbed" amount) grew from +0.6 W/m 2 (2009 est. [1]) to above +1.0 W/m 2 in 2019 [2]. Jul 10, 2017 · 3. Color of Your Roof. Yup, even the color of your roof can affect the temperature of your home. In fact, a federal study has shown that the plywood under dark roofs in direct sunlight is consistently 10 to 15°F hotter than the plywood boards under light-colored roofs. If you think back to your elementary science class, it’s pretty easy to ... The animation on the right shows the change in global surface temperatures. Dark blue shows areas cooler than average. Dark red shows areas warmer than average. Short-term variations are smoothed out using a 5-year running average to make trends more visible in this map. The data shown are the latest available, updated annually.Jul 10, 2021 · Your air conditioner is designed to take the air temperature 30 degrees Fahrenheit lower than the outside temperature. On an average day, that’s probably enough, but if it’s really hot outside, then you’ll likely want the indoor temperature to come down more than 30 degrees, and your AC unit may struggle. You’ll need to accept that your ... Low 21. Sunny. Increasing cloudiness in the afternoon then 40 percent chance of showers late in the afternoon. Risk of a thunderstorm late in the afternoon. Wind becoming southwest 20 km/h in the afternoon. High 32. Humidex 40. UV index 7 or high. Cloudy with 60 percent chance of showers and risk of a thunderstorm.Heat Index Formula. This calculator uses the following basic formula to calculate the heat index: HI (Heat Index, °F) = C 1 + C 2 T + C 3 RH + C 4 T RH + C 5 T 2 + C 6 RH 2 + C 7 T 2 RH + C 8 T RH 2 + C 9 T 2 RH 2 + CF. Where: HI is the heat index (°F), T is the air temperature in Fahrenheit (°F), RH is the relative humidity (%),Jul 11, 2023 · The global mean temperature in June 2023 was 1.47 ± 0.09 °C (2.64 ± 0.16 °F) above the 1850 to 1900 average, which is frequently used as a benchmark for the preindustrial period. The global mean temperature anomaly in June 2023 exhibited a significant increase relative to May 2023 , rising more than 0.15 °C (0.27 °F). Outside of the TNZ exist the upper and lower critical tem-perature zones. When temperatures are in these zones the dog has to expend energy to maintain its body temperature. When this is no longer possible, hypo- or hyperthermia occurs. It is important to consider coat thickness and other specific breed Jun 28, 2018 · On a 100-degree day, even if the windows are cracked, the temperature inside the car can soar to about 119 degrees in just ten minutes. And to 129 in just 20 minutes. NBC 5. Even on a mild day at ... For example, if the air temperature is 100°F and the relative humidity is 55%, the heat index will be 124°F. When the relative humidity is low, the apparent temperature can actually be lower than the air temperature. For example, if the air temperature is 100°F and the relative humidity is 15%, the heat index is 96°F (use this calculator).The Missouri Department of Natural Resources assists in finding funding mechanisms for energy improvements, educates Missourians and promotes efficient use of energy resources for economic growth, a healthy environment, and a better Missouri for future generations. This includes efforts to bring innovative energy solutions to market ... May 14, 2019 · 140-190. Aluminum reflective coated. Up to 68 degrees cooler than black roofs. 125-140. Unpainted metal. 138-145, but feels hotter to the touch than a black roof. Painted Metal (ex: BASF Cool Paint) 105-115 or up to 42% cooler than unpainted metal. The rooftop temperature results from two different properties. Outside of the TNZ exist the upper and lower critical tem-perature zones. When temperatures are in these zones the dog has to expend energy to maintain its body temperature. When this is no longer possible, hypo- or hyperthermia occurs. It is important to consider coat thickness and other specific breed ambient temperature: In a computing context, ambient temperature is the air temperature of any environment where computers and related equipment are kept. The adjective ambient means "relating to the immediate surroundings."The ideal body temperature in adults is around 98.6°F (37°C), but this varies based on age, physical activity, and health. Body temperature also changes throughout the day. A temperature of ...
On a day when it’s warmer than 80 °F outside, and your A/C (with a clean filter) has been running for at least 15 minutes (to let the temperature in the ductwork stabilize), put a thermometer on the intake vent that’s closest to your inside cooling equipment. Keep it there for about 5-10 minutes and note the temperature. . The domain of es002 1.jpg is
Absolute humidity (expressed as grams of water vapor per cubic meter volume of air) is a measure of the actual amount of water vapor (moisture) in the air, regardless of the air's temperature. The higher the amount of water vapor, the higher the absolute humidity. For example, a maximum of about 30 grams of water vapor can exist in a cubic ... According to NOAA's 2021 Annual Climate Report the combined land and ocean temperature has increased at an average rate of 0.14 degrees Fahrenheit ( 0.08 degrees Celsius) per decade since 1880; however, the average rate of increase since 1981 has been more than twice as fast: 0.32 °F (0.18 °C) per decade. The amount of future warming Earth ...The optimal temperature for solar panels is around 25°C (77°F). Solar panels perform best under moderate temperatures, as higher or lower temperatures can reduce efficiency. For every degree above 25°C, a solar panel’s output can decrease by around 0.3% to 0.5%, affecting overall energy production.Oct 31, 2016 · Stellenbosch, South Africa. Stellenbosch’s annual weather data make it look like a microclimate supermodel: 71 (average annual high) by 50 (average annual low) by 36 (annual average rain in ... Absolute humidity (expressed as grams of water vapor per cubic meter volume of air) is a measure of the actual amount of water vapor (moisture) in the air, regardless of the air's temperature. The higher the amount of water vapor, the higher the absolute humidity. For example, a maximum of about 30 grams of water vapor can exist in a cubic ...Basically, the hotter it is and the higher the percentage of relative humidity, the riskier it is to work out. For example, if the temperature is 88 degrees, and the relative humidity is 85%, you ...Feels Like Temps. The Feels Like Temperatures map show what the outdoor temperature will feel like for the current day. Feels Like Index is a factored mixture of the Wind Chill Factor and the Heat ... This is sometimes referred to as a unit of standard atmospheres (atm). Total atmospheric mass is 5.1480×10 18 kg (1.135×10 19 lb), [40] about 2.5% less than would be inferred from the average sea level pressure and Earth's area of 51007.2 megahectares, this portion being displaced by Earth's mountainous terrain.Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. [2] Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depends on the temperature and pressure of the system of interest.The report examined the impacts of limiting the increase in global average temperature to well below 2 degrees Celsius (3.6 degrees Fahrenheit) above pre-industrial levels, and projected the impacts Earth is expected to see at both 1.5 degrees and 2 degrees Celsius warming above those levels. The 1.5-degree Celsius threshold represents the ...Outside of the TNZ exist the upper and lower critical tem-perature zones. When temperatures are in these zones the dog has to expend energy to maintain its body temperature. When this is no longer possible, hypo- or hyperthermia occurs. It is important to consider coat thickness and other specific breedBasically, the hotter it is and the higher the percentage of relative humidity, the riskier it is to work out. For example, if the temperature is 88 degrees, and the relative humidity is 85%, you ...RH = relative humidity in percent (%). The temperature (air or dew point) can be specified in Celsius (°C), Fahrenheit (°F) or Kelvin (°K). This calculator uses the following temperature conversion rules: 1 °C = 33.8 °F. 1 °C = 274.15 °K. Source: Martin Wanielista, Robert Kersten & Ron Eaglin, 1997 - Hydrology Water Quantity and Quality ...May 4, 2021 · The latest 1991–2020 U.S. Climate Normals are an update to the Normals for the previous 3 decades, 1981-2010. NOAA’s Climate Normals are statistical calculations of weather observations — such as temperature, precipitation and snowfall — from approximately 15,000 federal weather stations across the United States and its territories. Outdoor summer and winter design temperatures and relative humidity for US states and cities. The table below indicates the summer and winter design conditions in US states and cities. 7:30 am. 7:30 am.Feb 14, 2020 · If the air temperature is 100 degrees Fahrenheit with 55% humidity, for example, the heat index is 124 degrees. You feel much hotter because your sweat won't evaporate as easily. Conversely, if the heat index is lower—say 15%—that same 100 degrees actually would feel like 96. You can view the heat index chart at the National Weather Service ... The animation on the right shows the change in global surface temperatures. Dark blue shows areas cooler than average. Dark red shows areas warmer than average. Short-term variations are smoothed out using a 5-year running average to make trends more visible in this map. The data shown are the latest available, updated annually.If the air temperature is 100 degrees Fahrenheit with 55% humidity, for example, the heat index is 124 degrees. You feel much hotter because your sweat won't evaporate as easily. Conversely, if the heat index is lower—say 15%—that same 100 degrees actually would feel like 96. You can view the heat index chart at the National Weather Service ....