Heat Index
The Heat index, takes into account air temperature and relative humidity, to be an indication of how hot it feels.
The method of this index uses a multiple regression and Apparent Temperature’s calculation of relative humidity.
Here we have two methods: Heat Index Simplified and Heat Index Adjusted. As is set out by https://www.wpc.ncep.noaa.gov/html/heatindex_equation.shtml
We carry out the calculation in Fahrenheit and then convert to Celsius in keeping with the other thermal indices in this library.
How To Use
Simplified Heat Index
You need 2m temperature in Kelvin and, optionally, relative humidity such as saturation vapour pressure (because this can be directly calculated from 2m temperature). Please use numpy arrays.
It returns the heat index in Celsius.
calculate_heat_index_simplified(2m_temperature,relative_humidity)
Adjusted Heat Index
You need 2m temperature and 2m dew point temperature in Kelvin.
It returns the heat index in Celsius.
calculate_heat_index_adjusted(2m_temperature,2m_dew_point_temperature)
Interpret the Output
Here is a suggested way for you to interpret heat index outputs. However, it is by no means the only way to go about defining thermal stress. Heat Index and Apparent Temperature have the same thresholds.
Apparent Temperature Range °C |
Effect on Body |
|---|---|
27-32 |
Fatigue possible with prolonged exposure and/or physical activity |
32-39 |
Heat stroke, heat cramps, or heat exhaustion possible with prolonged exposure and/or physical activity |
39-51 |
Heat cramps or heat exhaustion likely, and heat stroke possible with prolonged exposure and/or physical activity |
51< |
Heat stroke highly likely |