When the formula applies
Wind chill formulas are designed for cold, windy conditions and exposed skin. They do not measure actual air temperature, and they do not account for clothing, sun exposure, humidity or personal risk factors.
Example
An air temperature of -5 C with a 30 km/h wind feels colder than still air at -5 C because wind removes heat from exposed skin faster. The result should be read as an apparent temperature, not as a thermometer reading.
Common mistakes
Do not use wind chill for warm weather, indoor comfort or heat stress. For hot and humid conditions, use a heat index calculator instead. Wind measured at a weather station may also differ from wind around buildings, trees or hills.
Safety note
Use official weather warnings for safety decisions in severe cold, especially for children, older adults, outdoor workers and anyone with health conditions affected by cold exposure.
Last reviewed: 2026-05-17