Heat Index Risk Calculator

Estimate how hot it feels outside and check basic heat-risk level.

Air temperature
(°C)

Outdoor air temperature.

Relative humidity
(%)

Higher humidity makes heat feel worse.

Activity
level

Activity increases practical heat risk.

Main result
view

Choose the main output.

Heat index result

Risk level

Approximate estimate only. Real heat stress also depends on sun exposure, wind, hydration, clothing, age, and health.