Outdoor & Survival
Heat index calculator
Summer feels-like temperature from heat and humidity.
- Instant
- Free
- Private (processed locally)
- No sign-up
Compute the feels-like temperature
Enter the temperature and the humidity: the tool shows the feels-like temperature and the risk level.
Example
| Input | Value |
|---|---|
| Temperature | 32 °C |
| Humidity | 70% |
| Feels like | ≈ 40 °C |
NWS formula, in shade. 100% local calculation.
Humidity is also read through the dew point: above 21 °C (70 °F) the air feels oppressive. Work it out with our dew point calculator.
Frequently asked questions
When is the index valid?
Mainly above 27 °C; below that the sensation is close to the real temperature.
And in the sun?
The formula is for shade. In full sun the sensation can rise by several degrees.
When does it get dangerous?
Above ~41 °C felt, heatstroke risk rises sharply: hydrate and stay cool.