Wind Chill Calculator

How to use the wind chill calculator

1. Enter the air temperature and choose °F or °C.
2. Enter the wind speed in mph or km/h.
3. Read the wind chill, the feels-like temperature.
4. Copy the link to save or share it.

What wind chill is

Wind chill is how cold the air feels on exposed skin once the wind is taken into account. Moving air carries heat away from your body faster than still air, so a breezy 30°F day feels colder than a calm one. This wind chill calculator gives that feels-like temperature, also called the wind chill factor, the wind chill index, or the real feel, so you can judge the risk before going out.

The formula and its limits

The tool uses the US National Weather Service wind chill formula introduced in 2001, which combines temperature and wind speed. It is only defined within a range: at or below 50°F (10°C) with a wind of at least 3 mph (4.8 km/h). Outside that range, wind chill is not meaningful, so rather than print a misleading number the tool tells you it does not apply. This keeps the result honest.

Source: US National Weather Service wind chill temperature index.

Why it matters

Wind chill is a safety measure, not just a comfort one. As the feels-like temperature drops, exposed skin can develop frostbite, and the colder the wind chill, the faster it happens. Weather services issue wind chill warnings for this reason. Use the number to decide how much to cover up and how long is safe outside, and remember it describes exposed skin, not the actual air temperature.

A worked example

At an air temperature of 20°F with a 15 mph wind, the wind chill is about 6°F. The thermometer reads 20, but bare skin loses heat as though it were 6 degrees, which is why dressing for the wind chill rather than the reading matters.

FAQ

What is wind chill?

Wind chill is the feels-like temperature in cold, windy weather. Wind carries body heat away faster, so the air feels colder than the thermometer reads. The tool works it out from temperature and wind speed.

When does wind chill apply?

Only at or below 50°F (10°C) with wind of at least 3 mph (4.8 km/h). Outside that range the formula is not defined, and the tool says so instead of guessing.

Is wind chill the actual temperature?

No. It describes how cold exposed skin feels, not the air temperature, which does not change. A thermometer still reads the true temperature.

Why does wind make it feel colder?

Moving air strips away the thin layer of warmth next to your skin faster than still air, so your body loses heat more quickly and the cold feels sharper.

Is my information private?

Yes. Everything is calculated in your browser and nothing you enter is uploaded or saved.