The formula
How it works
Wind chill is how cold the air feels on your skin once the wind is factored in. Moving air strips away the thin warm layer your body creates, so a breezy day feels far colder than the thermometer alone suggests.
FAQ
When does wind chill apply?
The standard formula is defined for temperatures at or below 10 °C (50 °F) and winds above about 5 km/h (3 mph). Outside that range, wind has little cooling effect and the number is not meaningful.
Can wind chill freeze me faster?
Yes. A lower feels-like temperature means exposed skin loses heat more quickly, raising the risk of frostbite. Weather services issue wind chill warnings for exactly this reason.
Does wind chill affect car engines or water pipes?
No — wind chill only describes how exposed skin and other living tissue lose heat. Objects like engines, pipes and thermometers cool to the actual air temperature regardless of wind, since they don’t generate their own warmth the way a body does.
Why do different countries report different wind chill numbers for the same weather?
Some regions use the newer North American formula used here, while others use older formulas or different reference wind speeds, which can give slightly different results for identical conditions. Always compare wind chill values calculated the same way.
What wind speed should I use if forecasts show gusts?
Use the sustained wind speed rather than gust speed for a typical wind chill reading, since gusts are brief. If you are dressing for repeated exposure to gusts, checking the chill at gust speed gives a worst-case estimate.
Is wind chill the same as “feels like” temperature in an app?
Often yes in cold weather, but many apps blend wind chill with other effects — like humidity or sun — into a single feels-like number, so the two can differ slightly. Wind chill specifically isolates the cooling effect of wind.
Why does wind chill matter less as temperatures rise?
The formula is only meaningful at or below about 10 °C (50 °F), because above that, wind has little extra cooling effect on skin and the body regulates temperature well without it. That’s why the calculator, like official guidance, treats warmer, breezy days differently.
About the wind chill calculator
This calculator works out the wind chill — the temperature your skin actually feels — from the air temperature and the wind speed. Your body warms a thin layer of air right against your skin, and wind constantly blows that warm layer away, forcing your body to reheat and making you feel colder. Wind chill puts a single feels-like number on that effect, which is why forecasts quote it on cold, windy days.
How to use it
Pick metric (°C and km/h) or imperial (°F and mph), then enter the air temperature and the wind speed. The calculator returns the wind chill temperature. For example, an air temperature of −5 °C with a 30 km/h wind feels like about −13 °C. The colder the air and the stronger the wind, the bigger the gap between the real temperature and how it feels — which is what you need to know before heading outside.
The formula
The modern formula, used across North America, is in metric units, where is the air temperature in °C and is the wind speed in km/h. The imperial version uses different constants but the same shape. The wind speed is raised to the power 0.16, which captures how the cooling effect grows fast at first and then levels off as the wind gets stronger.
Where it is used
Weather services use wind chill to issue cold-weather and frostbite warnings, and it guides decisions about school closures, outdoor work and event safety. Hikers, skiers and winter athletes use it to dress correctly and judge exposure risk. The military and occupational-safety bodies build it into cold-work guidelines, since the feels-like temperature — not the raw reading — determines how fast unprotected skin is in danger.