Taking into account the influence of wind and humidity.
The wind removes a layer of heated air from the skin's surface, leading to the sensation of colder weather. This phenomenon was studied by American polar explorers at the beginning of World War II. Based on measurements of the freezing temperature of water depending on wind speed, they developed the so-called wind chill index.
With its help, one can determine the temperature at which water freezes at the same rate in calm weather conditions for each combination of temperature and wind strength. For example, at a wind speed of 2 m/s, a temperature of −15 °C feels like −20 °C. There is also a similar index for heat (Humindex), which takes into account the effect of humidity on the evaporation of moisture from the skin.
