Heat Index Calculator
Calculate the heat index (feels-like temperature) based on air temperature and relative humidity. The heat index measures how hot it feels when relative humidity is factored in with the actual air temperature.
Weather Conditions
°F
70°F 80°F 90°F 100°F 110°F 120°F
%
0% 20% 40% 60% 80% 100%
Temperature
60%
Humidity
Heat Index Results
Heat Index (Feels Like)
–°F
Temperature: 90°F
Humidity: 60%
Dew Point: –°F
Risk Level
Enter values to calculate risk level
Heat Index Chart
What is Heat Index?
The heat index is a measure of how hot it feels when relative humidity is factored in with the actual air temperature. Your body cools itself by sweating, but when humidity is high, sweat doesn’t evaporate as easily, making it feel hotter than the actual temperature.
Safety Tips
- Stay hydrated with water
- Take breaks in shaded or air-conditioned areas
- Wear lightweight, light-colored clothing
- Avoid strenuous activities during peak heat