Wind Chill
Wind chill is how cold the air feels on exposed skin once wind is taken into account. Wind strips heat from the body faster than still air does, so the wind chill temperature is lower than the air temperature. At 0°F with a 15 mph wind, the wind chill is -19°F, and exposed skin can freeze in 30 minutes.
Why It Matters
Wind chill describes how fast exposed skin loses heat, which is what drives the risk of frostbite and hypothermia. It is the number to dress for on a cold, windy day.
It applies to people and animals, not objects. Wind cannot cool a car radiator or a water pipe below the actual air temperature. It only shortens the time the object takes to get there.
Wind Chill at Selected Air Temperatures and Wind Speeds
| Air temperature | 5 mph wind | 15 mph wind | 25 mph wind | 35 mph wind |
|---|---|---|---|---|
| 40°F | 36°F | 32°F | 29°F | 28°F |
| 30°F | 25°F | 19°F | 16°F | 14°F |
| 20°F | 13°F | 6°F | 3°F | 0°F |
| 10°F | 1°F | -7°F | -11°F | -14°F |
| 0°F | -11°F | -19°F | -24°F | -27°F |
| -10°F | -22°F | -32°F | -37°F | -41°F |
| -20°F | -34°F | -45°F | -51°F | -55°F |
Calculated from the National Weather Service wind chill formula and rounded to the nearest degree.
How It Is Calculated
- The NWS formula uses only air temperature (T, in °F) and wind speed (V, in mph): 35.74 + 0.6215T - 35.75(V^0.16) + 0.4275T(V^0.16).
- Wind chill is defined only for air temperatures at or below 50°F and wind speeds above 3 mph.
- The wind speed is for a height of about 5 feet, the height of a face, adjusted from the standard 33-foot anemometer height.
- Sunshine is not included. Bright sun can make it feel 10°F to 18°F warmer than the wind chill value.
- Since October 1, 2024, the National Weather Service issues Extreme Cold Watches and Warnings and Cold Weather Advisories in place of Wind Chill Watches, Warnings, and Advisories.
Frequently Asked Questions
At what wind chill does frostbite happen?
The colder the wind chill, the faster exposed skin freezes. At a wind chill of -19°F (0°F air with a 15 mph wind), exposed skin can freeze in 30 minutes, and colder or windier conditions shorten that time. The National Weather Service wind chill chart shows the frostbite time for each combination.
Is wind chill the same as the feels-like temperature?
Wind chill is the cold-weather kind of feels-like temperature. Feels-like is the umbrella term: forecasts report wind chill when it is cold and windy and the heat index when it is hot and humid.
Can wind chill freeze pipes or a car radiator?
Not below the actual air temperature. Wind chill only shortens the time an object takes to cool. With an air temperature of -5°F and a wind chill of -31°F, a car radiator will not drop below -5°F.
Related Terms
Heat Index
The heat index is how hot it feels when relative humidity is combined with the air temperature. Humid air slows the evaporation of sweat, so the body cools less efficiently and feels hotter than the thermometer reads. At 100°F with 55% relative humidity, the heat index is 124°F.
Frost
Frost is a thin layer of ice crystals that forms on surfaces when they cool to 32°F (0°C) or below and water vapor in the air freezes onto them. It is the surface that has to reach freezing, not the air: frost can form while the official air temperature is still in the mid 30s.
Blizzard
A blizzard is a storm with sustained winds or frequent gusts of 35 mph or more and falling or blowing snow that frequently reduces visibility to below a quarter mile, lasting 3 hours or longer. The National Weather Service definition has no snowfall or temperature requirement: wind and visibility make a blizzard.
Polar Vortex
The polar vortex is a large area of low pressure and cold air surrounding each of Earth's poles. It always exists, weakening in summer and strengthening in winter. During Northern Hemisphere winter it often expands, sending Arctic air south with the jet stream and producing cold outbreaks across the United States.
Alberta Clipper
A fast-moving low-pressure system that originates near Alberta, Canada, and tracks southeast across the northern United States. Clippers typically bring light snow (1-4 inches) followed by bitter cold and gusty winds.
Black Ice
A thin, transparent layer of ice on road surfaces that is nearly invisible, making it extremely dangerous for drivers. Black ice forms when temperatures drop rapidly after rain or from refreezing meltwater, often at night or in shaded areas.
Wind Chill: Guides and Explainers
These explainers connect this definition to real-world forecasting and decision-making.
In-depth guide
What Does 'Feels Like' Temperature Mean? Wind Chill vs Feels Like Explained
What feels-like temperature means, how wind chill and heat index differ, the frostbite times on the NWS chart, and why Extreme Cold Warnings replaced the Wind Chill Warning.
Weather Education
Watch vs Warning vs Advisory vs Outlook: NWS Weather Alerts Explained
Learn the difference between a weather watch, warning, advisory, and outlook, what a Special Weather Statement means, and when to prepare versus take immediate action.
Weather Education
Frost Advisory vs Freeze Warning vs Hard Freeze: What Each One Means
A Frost Advisory usually means lows of 33 to 36°F, a Freeze Warning 32°F or colder, and a hard freeze about 28°F or colder. Learn why frost forms above freezing, why the alerts stop in late fall, and what to protect at each level.
Helpful Tools and Hubs
Use these pages to apply the concept, compare conditions, or follow related weather workflows.
Tool
Wind Chill Calculator
A free tool for working this out with your own numbers.
Seasonal Hub
Winter Weather Guide
Find practical explainers on snow, freezing rain, wind chill, and winter travel risk.
Tool
Wind Speed Converter
Convert between mph, km/h, knots, and m/s for wind reports and forecasts.
Tool
Clothing Suggestion Tool
Get outfit suggestions matched to temperature, wind, rain, and activity level.
Sources
Explore Other Terms
Tropical Depression
An organized system of clouds and thunderstorms with defined circulation and maximum sustained winds of 38 mph or less. Tropical depressions can strengthen into tropical storms and eventually hurricanes.
Nor'easter
A storm along the East Coast with winds blowing from the northeast. Nor'easters can bring heavy snow, rain, and coastal flooding, especially from Virginia to New England. The most powerful nor'easters rival hurricanes in intensity.
Small Craft Advisory
A Small Craft Advisory is a National Weather Service alert for winds or seas that are hazardous to small boats in coastal and Great Lakes waters. The wind and sea thresholds are set separately for each geographic area. There is no precise definition of a small craft: any vessel that the conditions could affect counts.
Red Flag Warning
A Red Flag Warning is a National Weather Service alert that weather conditions could cause extreme fire behavior. It is issued when those conditions are occurring or expected within 24 hours. Typical criteria combine dry fuels with sustained winds of 15 mph or more and relative humidity of 25% or less, and exact thresholds vary by state and local office.
Jet Stream
A jet stream is a relatively narrow band of strong wind in the upper atmosphere, typically around 30,000 feet, that blows from west to east. The polar jet sits between 50° and 60° latitude and the subtropical jet near 30°. Jet streams follow the boundaries between cold and warm air and steer the storm systems below them.
Kp Index
The Kp index is a 0 to 9 scale of global geomagnetic activity, reported in 3-hour intervals from ground-based magnetometers. A Kp of 5 or higher indicates a geomagnetic storm, and the values map onto NOAA's G-scale from G1 (Kp 5) to G5 (Kp 9). The higher the Kp, the farther from the poles the aurora can be seen.
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In the WeatherAI App
WeatherAI shows a feels-like temperature with current conditions, and Standard and Pro subscribers can set a custom notification rule on feels-like temperature, checked at a time of day they choose.
Availability, coverage, update frequency, and alert delivery vary by data source, region, subscription plan, device permissions, and service conditions. WeatherAI supplements official sources and is not an emergency notification service. For life-safety decisions, rely on your national weather service, local emergency management, and official warning channels.