Wind Chill Calculator and Chart
How cold the wind makes it feel on bare skin, from the National Weather Service formula, with the time it takes to get frostbite.
Wind chill calculator
Wind chill: -19°F (-29°C)
0°F with a 15 mph wind feels like -19°F (-29°C) on bare skin, 19°F colder than the air.
Frostbite risk: exposed skin can freeze in 30 minutes or less. Cover your face, ears and hands.
Wind chill is defined for air temperatures at or below 50°F (10°C) and winds above 3 mph (5 km/h). Use the sustained wind from your forecast, not gusts. Riding a motorcycle or a snowmobile? Use your speed as the wind (see below).
Wind chill chart
Find the air temperature across the top and the wind speed down the side. The number where they meet is the wind chill in °F. Shaded cells show how fast exposed skin can get frostbite, as on the NWS chart. Example: 0°F with a 15 mph wind feels like -19°F, and frostbite can set in within 30 minutes.
Scroll the chart sideways for colder temperatures.
| Wind (mph) | Air temperature (°F) | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 40 | 35 | 30 | 25 | 20 | 15 | 10 | 5 | 0 | -5 | -10 | -15 | -20 | -25 | -30 | -35 | -40 | -45 | |
| 5 | 36 | 31 | 25 | 19 | 13 | 7 | 1 | -5 | -11 | -16 | -22 | -28 | -34 | -40 | -46 | -52 | -57 | -63 |
| 10 | 34 | 27 | 21 | 15 | 9 | 3 | -4 | -10 | -16 | -22 | -28 | -35 | -41 | -47 | -53 | -59 | -66 | -72 |
| 15 | 32 | 25 | 19 | 13 | 6 | 0 | -7 | -13 | -19 | -26 | -32 | -39 | -45 | -51 | -58 | -64 | -71 | -77 |
| 20 | 30 | 24 | 17 | 11 | 4 | -2 | -9 | -15 | -22 | -29 | -35 | -42 | -48 | -55 | -61 | -68 | -74 | -81 |
| 25 | 29 | 23 | 16 | 9 | 3 | -4 | -11 | -17 | -24 | -31 | -37 | -44 | -51 | -58 | -64 | -71 | -78 | -84 |
| 30 | 28 | 22 | 15 | 8 | 1 | -5 | -12 | -19 | -26 | -33 | -39 | -46 | -53 | -60 | -67 | -73 | -80 | -87 |
| 35 | 28 | 21 | 14 | 7 | 0 | -7 | -14 | -21 | -27 | -34 | -41 | -48 | -55 | -62 | -69 | -76 | -82 | -89 |
| 40 | 27 | 20 | 13 | 6 | -1 | -8 | -15 | -22 | -29 | -36 | -43 | -50 | -57 | -64 | -71 | -78 | -84 | -91 |
| 45 | 26 | 19 | 12 | 5 | -2 | -9 | -16 | -23 | -30 | -37 | -44 | -51 | -58 | -65 | -72 | -79 | -86 | -93 |
| 50 | 26 | 19 | 12 | 4 | -3 | -10 | -17 | -24 | -31 | -38 | -45 | -52 | -60 | -67 | -74 | -81 | -88 | -95 |
| 55 | 25 | 18 | 11 | 4 | -3 | -11 | -18 | -25 | -32 | -39 | -46 | -54 | -61 | -68 | -75 | -82 | -89 | -97 |
| 60 | 25 | 17 | 10 | 3 | -4 | -11 | -19 | -26 | -33 | -40 | -48 | -55 | -62 | -69 | -76 | -84 | -91 | -98 |
Source: National Storms (nationalstorms.com), CC BY 4.0, data from the National Weather Service wind chill formula and chart (effective November 1, 2001).
Wind chill chart in °C and km/h
| Wind (km/h) | Air temperature (°C) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 5 | 0 | -5 | -10 | -15 | -20 | -25 | -30 | -35 | -40 | -45 | -50 | |
| 10 | 3 | -3 | -9 | -15 | -21 | -27 | -33 | -39 | -45 | -51 | -57 | -63 |
| 20 | 1 | -5 | -12 | -18 | -24 | -30 | -37 | -43 | -49 | -56 | -62 | -68 |
| 30 | 0 | -6 | -13 | -19 | -26 | -33 | -39 | -46 | -52 | -59 | -65 | -72 |
| 40 | -1 | -7 | -14 | -21 | -27 | -34 | -41 | -47 | -54 | -61 | -68 | -74 |
| 50 | -1 | -8 | -15 | -22 | -29 | -35 | -42 | -49 | -56 | -63 | -69 | -76 |
| 60 | -2 | -9 | -16 | -23 | -30 | -36 | -43 | -50 | -57 | -64 | -71 | -78 |
| 70 | -2 | -9 | -16 | -23 | -30 | -37 | -44 | -51 | -58 | -65 | -72 | -79 |
| 80 | -3 | -10 | -17 | -24 | -31 | -38 | -45 | -52 | -59 | -67 | -74 | -81 |
| 90 | -3 | -10 | -17 | -25 | -32 | -39 | -46 | -53 | -60 | -68 | -75 | -82 |
| 100 | -3 | -11 | -18 | -25 | -32 | -40 | -47 | -54 | -61 | -69 | -76 | -83 |
Same formula in metric units. NWS publishes frostbite shading only for its °F chart; use the calculator above for frostbite times in any unit.
The wind chill formula
The National Weather Service has used this formula since November 1, 2001 (Environment Canada uses the same one):
Wind chill (°F) = 35.74 + 0.6215T − 35.75(V0.16) + 0.4275T(V0.16)
where T is the air temperature in °F and V is the wind speed in mph.
In metric units: wind chill (°C) = 13.12 + 0.6215T − 11.37(V0.16) + 0.3965T(V0.16), with T in °C and V in km/h.
Valid range: NWS defines wind chill only for air temperatures at or below 50°F (10°C) and winds above 3 mph (about 5 km/h). With wind of 3 mph or less, the wind chill is the air temperature.
The formula estimates how cold bare skin on your face feels, by calculating how fast the wind carries heat away from it. It is based on a model of a human face, takes the wind measured at the standard 33-foot height and lowers it to about 5 feet (face height), and assumes a clear night with no sun. NWS says it was tested on 12 adult volunteers. It replaced the 1945 Siple and Passel index, which gave much colder numbers. That's why wind chill records set before 2001 often sound colder than any today.
What wind chill can't do: it can't cool anything below the air temperature. At 35°F with a 30 mph wind the wind chill is 22°F, but water won't freeze and your car's radiator won't drop below 35°F. Wind only makes warm things (like skin) reach the air temperature faster.
Motorcycle wind chill chart
On a motorcycle, your riding speed is the wind. Add it to any headwind and look up the total below. This is the same NWS formula with riding speed as the wind speed, in °F.
| Air temp | 30 mph | 40 mph | 50 mph | 60 mph | 70 mph | 80 mph |
|---|---|---|---|---|---|---|
| 50°F | 42°F | 41°F | 40°F | 39°F | 38°F | 38°F |
| 45°F | 35°F | 34°F | 33°F | 32°F | 31°F | 30°F |
| 40°F | 28°F | 27°F | 26°F | 25°F | 24°F | 23°F |
| 35°F | 22°F | 20°F | 19°F | 17°F | 16°F | 16°F |
| 30°F | 15°F | 13°F | 12°F | 10°F | 9°F | 8°F |
| 25°F | 8°F | 6°F | 4°F | 3°F | 2°F | 1°F |
| 20°F | 1°F | -1°F | -3°F | -4°F | -6°F | -7°F |
Know the limits before you trust these numbers:
- The formula stops at 50°F. Above that, NWS defines no wind chill, so there is no honest number for a 60°F ride at highway speed, even though it feels cold.
- It was built for a person's face in the wind, with the wind measured 33 feet up and lowered to face height (about 5 feet). On a bike the air hits you at full riding speed, so bare skin is probably a bit colder than the table shows.
- It assumes a clear night with no sun. Sunshine makes it feel warmer.
- It applies only to bare skin. A full-face helmet, gloves and a windproof layer block most of it. Your engine and the bike itself never cool below the air temperature.
Frostbite and hypothermia
Frostbite freezes skin and the tissue under it, most often on the nose, ears, cheeks, chin, fingers and toes. It can only happen when the air temperature is below freezing (32°F). The first signs are redness or pain. Then the skin turns white or grayish-yellow, feels firm or waxy, and goes numb. The numbness is why people often don't notice it. What to do: get somewhere warm and get medical care. Put the affected skin in warm (not hot) water. Don't rub it, and don't warm it with a heating pad, heat lamp, fireplace or stove, because numb skin burns easily. Don't walk on frostbitten feet unless you have to.
Hypothermia is a dangerously low body temperature, when the body loses heat faster than it can make it. It can happen above 40°F if you're wet. Warning signs are shivering, exhaustion, confusion, fumbling hands, memory loss, slurred speech and drowsiness. Babies may have bright red, cold skin and very little energy. A body temperature below 95°F is an emergency. What to do: get medical help. Move the person somewhere warm, take off wet clothes, and warm the center of the body first (chest, neck, head and groin) under dry blankets. Warm drinks help a conscious person, but no alcohol. If the person is unconscious and has no pulse or is barely breathing, call 911 and start CPR.
The people most at risk are older adults without enough heat, food or clothing, babies sleeping in cold rooms, people outdoors for a long time (people without homes, hikers, hunters, outdoor workers), and people who have been drinking heavily. Sources: CDC, Preventing hypothermia and frostbite and its frostbite fact sheet; National Weather Service, cold weather safety.
Coldest wind chills in 59 big US cities
We checked the main airport weather station in 59 large and cold US cities. The coldest wind chills on record, with today's formula:
- Duluth, MN: -68°F on January 28, 1966
- Bismarck, ND: -64°F on December 31, 1967
- Great Falls, MT: -63°F on December 24, 1983
- Fargo, ND: -61°F on January 19, 1985
- Chicago, IL: -58°F on January 10, 1982
- Sioux Falls, SD: -57°F on December 24, 1983
- Minneapolis, MN: -57°F on December 24, 1983
- Green Bay, WI: -57°F on January 15, 1972
- Cheyenne, WY: -56°F on January 11, 1963
- Milwaukee, WI: -56°F on January 10, 1982
Most days a winter with a wind chill below 0°F (1996–97 through 2025–26): Fargo 73 days a winter; Duluth 65 days a winter; Bismarck 61 days a winter; Sioux Falls 47 days a winter; Minneapolis 45 days a winter.
Every city: Albuquerque, NM · Atlanta, GA · Austin, TX · Baltimore, MD · Billings, MT · Bismarck, ND · Boise, ID · Boston, MA · Buffalo, NY · Burlington, VT · Charlotte, NC · Cheyenne, WY · Chicago, IL · Cincinnati, OH · Cleveland, OH · Columbus, OH · Dallas, TX · Denver, CO · Des Moines, IA · Detroit, MI · Duluth, MN · Fargo, ND · Grand Rapids, MI · Great Falls, MT · Green Bay, WI · Hartford, CT · Houston, TX · Indianapolis, IN · Jacksonville, FL · Kansas City, MO · Las Vegas, NV · Los Angeles, CA · Louisville, KY · Madison, WI · Manchester, NH · Memphis, TN · Miami, FL · Milwaukee, WI · Minneapolis, MN · Nashville, TN · New York, NY · Oklahoma City, OK · Omaha, NE · Philadelphia, PA · Phoenix, AZ · Pittsburgh, PA · Portland, ME · Portland, OR · Rochester, NY · Salt Lake City, UT · San Antonio, TX · San Diego, CA · San Francisco, CA · Seattle, WA · Sioux Falls, SD · Spokane, WA · St. Louis, MO · Syracuse, NY · Washington, DC
How we count
For each city we use its main airport weather station. For every day we take the lowest wind chill from that day's observations (the NWS 2001 formula applied to each one; when the wind is 3 mph or less, the air temperature). Days below 0°F are days when the wind chill reached -1°F or colder, averaged over the 30 winters 1996–97 through 2025–26, counting only winters with nearly complete records (a city needs 25 or more). The coldest wind chill on record is the coldest day since the station's daily record starts (as early as 1940), with today's formula applied to the old observations too. That makes it milder than the record NWS announced at the time with the old formula, which ran much colder. We check each record against that day's hourly observations, and skip a day when the low rests on a single reading. Wind instruments moved and changed over the decades, so old records are less certain than recent ones. An airport can be windier and colder than a sheltered neighborhood.
More winter pages: snowfall totals · snowiest US cities this winter · white Christmas odds by city
Sources
Wind chill formula, valid range and chart: National Weather Service, Wind Chill Chart (chart PDF, effective November 1, 2001) and wind chill calculation. Frostbite times: the shading on the NWS chart, read cell by cell. Frostbite and hypothermia: Centers for Disease Control and Prevention, Preventing hypothermia and frostbite. City records and day counts: our own calculations from hourly airport (ASOS) observations collected by NOAA, the National Weather Service and the FAA, from the Iowa Environmental Mesonet archive (Iowa State University). Neither NOAA nor IEM has reviewed them. This page is not affiliated with the National Weather Service.