Heat Index
What hot weather really feels like once humidity is factored in.
Enter values
°C
%
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The formula
NWS Rothfusz regression on temperature and relative humidity
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Frequently asked questions
Why does humidity make heat feel worse?+
Your body cools by evaporating sweat. Humid air slows that evaporation, so heat builds up — the heat index estimates the temperature that would feel equivalent in dry air.
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