Weather Calculator

Wind Chill Calculator

Enter the air temperature and wind speed to get the wind chill in °F or °C, and how quickly exposed skin could get frostbite according to the National Weather Service wind chill chart. Wind chill is how cold it feels on your skin: 0°F with a 15 mph wind feels like -19°F, cold enough for frostbite in 30 minutes.

Air Temperature (°F)

Wind Speed (mph)

Wind Chill (Feels Like)

6°F

-14°C

Outside the frostbite bands

Frostbite is unlikely within 30 minutes, but long exposure can still cause it. Dress in layers and cover exposed skin.

Frostbite time from the NWS chart cell at 20°F and 15 mph, highlighted in the chart below.

Wind Chill Formula

The National Weather Service has used this index since November 1, 2001; it was developed jointly with Environment Canada. It models heat loss from a human face, adjusts wind measured at the standard 33-foot height down to face height, and assumes no sunshine.

Fahrenheit, wind in mph

WC = 35.74 + 0.6215T - 35.75V^0.16 + 0.4275TV^0.16

Celsius, wind in km/h

WC = 13.12 + 0.6215T - 11.37V^0.16 + 0.3965TV^0.16

Worked example: at 0°F with a 15 mph wind, V^0.16 = 1.542, so the wind chill is -19.4°F, which rounds to -19°F.

Wind chill is only defined at 50°F (10°C) or colder with wind above 3 mph (5 km/h). Bright sunshine can make it feel 10°F to 18°F warmer than the index shows.

Wind Chill Chart with Frostbite Times

The National Weather Service chart, in °F and mph. Find the air temperature across the top and the wind speed on the left. Shading shows how long it takes exposed skin to get frostbite.

30 minutes or less10 minutes or less5 minutes or less

Wind chill in °F for air temperatures from 40°F to -45°F and wind speeds from 5 to 60 mph, with frostbite times of 30, 10, and 5 minutes or less
mph \ °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 Weather Service Wind Chill Chart. Values are computed from the formula above; frostbite shading follows the official chart.

Understanding Wind Chill

What is Wind Chill?

Wind chill is the perceived decrease in air temperature felt by the body on exposed skin due to the flow of air. Wind increases the rate of heat loss from the body, making it feel colder than the actual temperature.

Why Does Wind Matter?

Your body warms a thin layer of air next to your skin. When wind blows, it carries away this warm air and your body must heat a new layer. The faster the wind, the faster heat is carried away, making you feel colder.

Cold Weather Safety Tips

Dress in layers, cover exposed skin (especially ears, nose, fingers, and toes), stay dry, and limit time outdoors in extreme cold. Watch for signs of frostbite: numbness, white or grayish skin, and firm or waxy feeling skin.

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Frequently Asked Questions

How is wind chill calculated?

The National Weather Service formula is wind chill (°F) = 35.74 + 0.6215T - 35.75V^0.16 + 0.4275TV^0.16, where T is the air temperature in °F and V is the wind speed in mph. The Celsius version is 13.12 + 0.6215T - 11.37V^0.16 + 0.3965TV^0.16, with wind in km/h. For example, 0°F with a 15 mph wind gives a wind chill of -19°F.

When does wind chill apply?

Wind chill is only defined for air temperatures at or below 50°F (10°C) with wind above 3 mph (5 km/h). In calm air, or when it is warmer than that, the wind chill is simply the air temperature.

How fast can you get frostbite in wind chill?

On the National Weather Service chart, exposed skin can get frostbite in 30 minutes or less once the wind chill reaches about -18°F (-28°C). Colder and windier conditions shorten that to 10 minutes or less, and then 5 minutes or less; the chart on this page shows where each band starts for every temperature and wind speed.

Can you get frostbite when it is above freezing?

No. The air temperature itself has to be below freezing for exposed skin to get frostbite, even if the wind chill is below freezing. Cold, wind, and wet clothing can still lead to hypothermia at temperatures above freezing.

Does wind chill affect cars, pipes, or other objects?

No. Wind chill only applies to people and animals. Wind cools an object such as a car radiator or a water pipe to the air temperature faster, but never below it. If it is -5°F with a wind chill of -31°F, the radiator will not get colder than -5°F.

Does sunshine change the wind chill?

Yes. The index assumes no sun, as on a clear night. Bright sunshine can make it feel 10°F to 18°F warmer than the wind chill shows.