Weather & air
Heat index calculator
Combine air temperature and humidity using the NWS calculation.
A clear answer. Here’s how.
Uses the NWS simple apparent-temperature estimate averaged with air temperature first. At 80°F or above, switches to the Rothfusz regression with its low/high humidity corrections. Assumes the standard shaded, light-wind context; extreme combinations can exceed the regression’s calibration. Reports the method used and does not infer an exposure limit or individual response.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Air temperature (°C)
- 32
- Relative humidity (%)
- 60
Example result
- Heat-index estimate (°C)
- 37.0742841218
- Heat-index estimate (°F)
- 98.7337114192
- Calculation method
- Rothfusz regression with applicable humidity corrections
Shaded, light-wind model. Extreme combinations can exceed its calibration; this is not an exposure limit.