Jak vypočítat Wind Chill
Co je Wind Chill?
The wind chill index measures the perceived decrease in air temperature felt by the body due to wind. Wind accelerates heat loss from exposed skin, making it feel colder than the actual temperature.
Vzorec
WC (°F) = 35.74 + 0.6215×T − 35.75×(V^0.16) + 0.4275×T×(V^0.16), where T=°F, V=mph
- WC
- Wind Chill (°F)
- T
- Air temperature (°F)
- V
- Wind speed (mph)
Průvodce krok za krokem
- 1Wind chill (°C) = 13.12 + 0.6215T − 11.37V^0.16 + 0.3965T×V^0.16
- 2T = air temperature (°C); V = wind speed (km/h)
- 3Only meaningful when T < 10°C and V > 4.8 km/h
- 4Wind speeds above 80 km/h have diminishing additional effect
Worked Examples
Vstup
Temperature −10°C, wind 40 km/h
Výsledek
Wind chill = 13.12 + 0.6215×(−10) − 11.37×40^0.16 + 0.3965×(−10)×40^0.16 ≈ −20°C
Frequently Asked Questions
Is wind chill real or just perceived?
Real: wind accelerates heat loss from exposed skin. Doesn't change actual air temperature, but speeds freezing.
What wind chill is dangerous?
Below −15°F: frostbite possible in 30 min. Below −25°F: frostbite in 10 min. Below −35°F: frostbite in <5 min.
How fast does wind speed need to be for wind chill?
3 mph minimum for meaningful effect. Higher speeds = greater wind chill. Wind chill maxes out around 60 mph.