Get the real feel of the weather with the standard formulas. Calculate heat index, wind chill, dew point, humidity, wet bulb temperature, cloud base and air density, and check the Beaufort and hurricane scales. Free and private, right in your browser. All 21 tools below are free, run in your browser, and need no sign-up.
Free heat index calculator using the NWS Rothfusz regression. Enter air temperature and relative humidity to find how hot it really feels.
Free wind chill calculator using the 2001 NWS/Environment Canada formula. Enter temperature and wind speed to find the wind chill temperature.
Free dew point calculator using the Magnus-Tetens formula. Enter temperature and relative humidity to find the dew point and comfort level.
Free feels like temperature calculator. Combines heat index in warm weather and wind chill in cold weather to show the real apparent temperature.
Free relative humidity calculator. Enter air temperature and dew point to find the relative humidity using saturation vapor pressure ratios.
Free absolute humidity calculator. Enter temperature and relative humidity to find grams of water vapor per cubic meter of air.
Free wet bulb temperature calculator using the Stull approximation. Enter air temperature and relative humidity to find the wet bulb temperature.
Free WBGT calculator estimating outdoor wet bulb globe temperature from air temperature, humidity and sun to gauge heat stress risk zones.
Free cloud base calculator using the Espy formula. Enter surface temperature and dew point to estimate the height of cumulus cloud bases.
Free snow to water ratio calculator. Convert snowfall depth to liquid water equivalent, or water to snow, using the ratio for your snow type.
Free Beaufort wind scale reference. Enter a wind speed to find its Beaufort force number, name and the sea and land effects that go with it.
Free Saffir-Simpson hurricane scale reference. Enter sustained wind speed to find the hurricane category and its expected damage.
Free air density calculator. Enter temperature, pressure and humidity to find moist air density in kilograms per cubic meter.
Free frost point calculator. Enter temperature and relative humidity to find the frost point, the temperature at which frost forms on surfaces.
Free rainfall volume calculator. Enter rainfall depth and a roof or catchment area to find the total water volume collected in liters and gallons.
Free growing degree days calculator. Enter daily high and low temperatures and a base temperature to find GDD accumulation for crop growth.
Free pressure altitude calculator. Enter field elevation and the altimeter setting to find pressure altitude for aviation performance planning.
Free density altitude calculator. Enter pressure altitude and temperature to find density altitude and gauge aircraft and engine performance loss.
Free UV index reference. Enter the UV index and your skin type to see the risk level, protection advice and estimated time to sunburn.
Free humidex calculator using the Canadian formula. Enter air temperature and dew point to find the humidex and how hot it feels with humidity.
Free lightning distance calculator. Enter the seconds between a lightning flash and thunder to find how far away the storm is and if it is a threat.
Yes. Every tool in this toolkit is completely free, with no sign-up and no usage limits.
Yes. They run in any modern web browser on phone, tablet or desktop, with nothing to install.
Yes. These tools run entirely in your browser, so nothing you enter is uploaded to a server.