Heat index is the temperature that it will feel like after taking into account the current air temperature and either the dew point or humidity.
Calculating the heat index can be done with a quite complicated and long formula. It is as such:
Heat Index Formula HI = −42.379 + 2.04901523 × T + 10.14333127 × R − 0.22475541 × T × R − 0.00683783 × T2 −0.05481717 × R2 + 0.00122874 × T2 × R + 0.00085282 × T × R2 −0.00000199 × T2 × R2 where HI = Heat Index, T = air temperature, R = relative humidity.
This means that it will feel like 110 degrees outside in the sun. In the shade this number will be less but in direct sunlight it will feel that hot.
According to the National Weather Service, a heat index between 105 and 129°F is dangerous, while anything 130°F or more is extremely dangerous.
The air temperature needs to be at least 80°F to calculate the heat index.
Create Date: July 26, 2024
Last Modified Date: July 30, 2024