This guide is for anyone checking a winter forecast to decide how to dress, how long to stay out, or whether kids and pets should go outside.
The wind chill is the number to dress for. Wind pulls heat away from your skin, so a windy 10°F day can be far more dangerous than a calm one.
The quick answer
The National Weather Service gives this example: if the temperature is 0°F and the wind is blowing at 15 mph, the wind chill is −19°F, and at that wind chill exposed skin can freeze in 30 minutes.1 Stronger wind or lower temperatures shorten that time.
How the chart works
The NWS chart crosses air temperature with wind speed. The formula behind it:1
Wind chill (°F) = 35.74 + 0.6215T − 35.75(V^0.16) + 0.4275T(V^0.16)
T is the air temperature in °F and V is the wind speed in mph. The NWS says wind chill is only defined for temperatures at or below 50°F and wind speeds above 3 mph.1 You don’t need to do the math: your weather app or the NWS forecast shows it.
What wind chill does and doesn’t mean
- It applies to people and animals. The NWS says objects, such as your car or pipes, will not cool below the actual air temperature.1
- Frostbite needs freezing air. The NWS says the air temperature has to be below freezing for frostbite to develop on exposed skin.1
- It’s a skin number. Our advice: dress for the wind chill, and cover skin, especially the face, ears and hands, when it drops well below zero.
Wind chill alerts
The NWS issues wind chill alerts based on local criteria, so the trigger values vary by region.2
| Alert | What it means (NWS)2 |
|---|---|
| Wind Chill Watch | Extremely cold air and strong winds could create dangerously low wind chill values |
| Wind Chill Advisory | Low wind chill values are expected, but not low enough for a warning |
| Wind Chill Warning | Very cold air and strong winds will create dangerously low wind chill values that will result in frostbite and lead to hypothermia if precautions are not taken |
When the wind chill is low
- Cover exposed skin and limit time outside.
- Learn the signs of frostbite and hypothermia.
- Shorten dog walks; see how cold is too cold for dogs.
- Keep a winter kit in the car in case you’re stuck.
Sources & method
How we researched this
- This is a research-based guide, not a hands-on product test.
- Every measurement and safety figure is attributed to the source it comes from. Where we give our own advice, we say so.
- We don’t rank or recommend specific products in this guide.
Sources
- Understanding Wind Chill, National Weather Service (NOAA). Accessed Nov 9, 2026.
- Winter Weather Warnings, Watches and Advisories, National Weather Service (NOAA). Accessed Nov 9, 2026.
Review history
- Published Nov 9, 2026.