Heat Index Calculator
Feels-like temperature from air temperature and humidity (°F).
Your result
This formula applies to air temperatures of 80°F or higher. Take breaks in shade, drink regularly and watch for dizziness or confusion.
Medical disclaimer: This tool is for education and is not medical advice. Read more.
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Frequently asked questions
What does the Heat Index Calculator do?
Feels-like temperature from air temperature and humidity (°F). Enter your values and the result and chart update instantly.
How accurate is it?
It uses published, widely used formulas. Results are estimates for education and planning, not a diagnosis. Talk to a qualified clinician about decisions affecting your health.
Is my information stored or shared?
No. All calculations run in your browser and nothing you type is sent to a server or saved.
What can I search to find this tool?
People find it by searching for: feels like temperature; heat index chart; how hot does it feel.