What is feels-like temperature?

Feels-like, or apparent, temperature is how hot or cold the air actually feels to a person, which can differ a lot from the thermometer. In warm weather high humidity slows the sweat that cools you, making it feel hotter. In cold weather wind strips heat from your skin, making it feel colder. This calculator combines all three inputs into a single number.

Which formulas does this use?

It uses the two official US National Weather Service equations. In warm conditions at or above eighty degrees Fahrenheit it applies the Rothfusz Heat Index regression using temperature and humidity. In cold conditions at or below fifty degrees Fahrenheit with meaningful wind it applies the Wind Chill formula using temperature and wind speed. In between, the air simply feels like the actual temperature.

Why does humidity only matter in the heat and wind only in the cold?

Because the two effects work through different mechanisms. Humidity affects how well your sweat can evaporate, which only matters when you are warm enough to sweat. Wind affects how fast heat is carried away from your skin, which is only significant when the air is already colder than you are. Outside those ranges each factor has little effect, so the formulas hand back the plain temperature.

Does it work in Celsius?

Yes. You can enter the temperature in Fahrenheit or Celsius and the wind in miles per hour or kilometres per hour. The calculator converts everything to the units the formulas expect, computes the result, and converts the feels-like value back to your chosen scale.

What is the Feels Like Temperature Calculator?

Calculate the feels-like temperature from air temperature, humidity and wind using the official NWS Heat Index and Wind Chill formulas. Works in Fahrenheit or Celsius. Runs entirely in your browser. It runs free in your browser on Gera Tools, with nothing uploaded.

Feels Like Temperature Calculator

Name: Feels Like Temperature Calculator
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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What the air actually feels like

The number on the thermometer rarely matches how the weather feels on your skin. A humid ninety degrees is punishing while a dry one is merely hot, and a still freezing day is bearable until the wind picks up. Feels-like temperature captures that difference, and this calculator computes it from three simple inputs — air temperature, humidity and wind speed.

Two official formulas, one answer

Meteorologists use two separate equations because heat and cold stress the body differently. In warm weather the National Weather Service Heat Index combines temperature and humidity to show how much hotter humid air feels, since moisture in the air slows the evaporation of sweat. In cold weather the Wind Chill formula combines temperature and wind speed, because moving air carries body heat away faster. This tool automatically applies whichever one fits the conditions and falls back to the plain temperature in mild weather.

Fahrenheit or Celsius, mph or km per hour

Weather is quoted in different units around the world, so the calculator accepts temperature in Fahrenheit or Celsius and wind in miles per hour or kilometres per hour. It converts your inputs to the units the formulas were built in, runs the regression, and returns the apparent temperature in your chosen scale along with how many degrees warmer or colder that is than the thermometer reads. It is a quick, accurate way to decide how to dress before you head out.