Heat Index Calculator

Calculate the heat index (feels like temperature) based on air temperature and humidity. Supports °C and °F.

%

Heat Index Tips

What is Heat Index?

Heat index is the "feels like" temperature, combining air temperature and humidity. High heat index can be dangerous.

Formula

The heat index formula is valid for T ≥ 27°C (80°F) and humidity ≥ 40%.

Safety

Stay hydrated, avoid strenuous activity in high heat, and seek shade or air conditioning when possible.