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Wind Chill Calculator (With NWS Frostbite Times)

Enter the air temperature and the wind speed to get the wind chill with the National Weather Service formula, and the frostbite time zone the NWS wind chill chart puts that combination in. It is the number to plan a cold shift around — not a work/warm-up schedule, which no federal source publishes.

°F
Actual air temperature in the shade. The wind chill formula is defined at or below 50 °F.
mph
Sustained wind at the work area. Add the wind a moving lift or an open truck bed makes.

Results are estimates for planning purposes and do not replace a competent person's evaluation or an engineer's design. Follow the OSHA standards that apply to your work and your employer's written program.

Where the frostbite zones start on the NWS chart

The National Weather Service wind chill chart shades three frostbite times. This table reads those bands off the chart: for each wind speed, the air temperature at which the crew crosses into each band.

Air temperature (°F) at which each NWS frostbite band begins, by wind speed
Wind30-minute band from10-minute band from5-minute band from
5 mph−10 °F−40 °Fnot reached on the chart
10 mph−5 °F−25 °Fnot reached on the chart
15 mph0 °F−20 °F−40 °F
20 mph0 °F−15 °F−35 °F
25 mph0 °F−10 °F−30 °F
30 mph5 °F−10 °F−25 °F
35-40 mph5 °F−5 °F−20 °F
45-50 mph5 °F−5 °F−15 °F
55 mph10 °F0 °F−15 °F
60 mph10 °F0 °F−10 °F

Read from the NWS Wind Chill Chart, effective 11/01/01. The chart runs from 40 °F to −45 °F and from 5 to 60 mph; outside those ranges there is no published band. Frostbite times apply to exposed skin — the face, the ears, the wrist between glove and sleeve.

Four things the number does not tell you

  • Frostbite needs air below freezing. NWS is explicit: wind chill cannot drag the real temperature below 32 °F. A −5 °F wind chill on a 40 °F day freezes nobody, and still drains body heat all afternoon.
  • Sunshine buys some of it back. Bright sunshine may raise the wind chill temperature by 10 to 18 °F, so the sheltered sunny wall and the exposed deck are two different jobs.
  • Wet beats cold. OSHA's cold stress guidance puts hypothermia above 40 °F for someone chilled by rain, sweat or immersion, and trench foot at temperatures as high as 60 °F with wet feet. Wind chill says nothing about wet.
  • There is no warm-up schedule here. No federal source publishes work/warm-up cycles; the table people quote is copyrighted ACGIH material. The schedule belongs in your employer's cold weather plan, and the day's wind chill belongs on the pre-task plan.

How it's calculated

Wind chill (National Weather Service, effective 11/01/2001)
Wind chill (°F) = 35.74 + 0.6215·T − 35.75·V^0.16 + 0.4275·T·V^0.16
T is air temperature in °F, V is wind speed in mph. Defined for temperatures at or below 50 °F and wind speeds above 3 mph.
Frostbite time zone
Read the NWS wind chill chart cell for the nearest 5 °F temperature and nearest 5 mph wind: 30 minutes, 10 minutes or 5 minutes
The chart's shaded bands are the published frostbite times. This calculator reports the band the nearest chart cell falls in — the chart is the source, not an interpolation.
Unit conversion
°F = °C × 9/5 + 32 · mph = km/h / 1.609344
Metric inputs are converted before the formula runs; the formula itself is defined in °F and mph.

Frequently asked questions

Wind chill (°F) = 35.74 + 0.6215T − 35.75(V^0.16) + 0.4275T(V^0.16), where T is the air temperature in °F and V the wind speed in mph. The National Weather Service put this version into service on November 1, 2001, and it applies at temperatures of 50 °F or below with wind above 3 mph.

The NWS wind chill chart shades three frostbite times: 30 minutes, 10 minutes and 5 minutes. At 0 °F with a 15 mph wind, the wind chill is −19 °F and exposed skin can freeze in 30 minutes. This calculator reports the zone your temperature and wind fall in on that chart.

No. The National Weather Service is explicit that the air temperature has to be below freezing for frostbite to develop on exposed skin; wind chill cannot pull the real temperature below freezing. A wind chill of 25 °F on a 45 °F day will not frostbite anyone — but it will still pull body heat and it can still cause hypothermia, especially on someone who is wet.

No. OSHA has no standard covering work in cold environments. Cold hazards are addressed under the General Duty Clause, Section 5(a)(1) of the OSH Act, which is why the wind chill, the clothing, the warm-up breaks and the buddy system belong in writing in your own cold weather plan.

Because the only work/warm-up table in circulation is ACGIH material, republished from a Saskatchewan source, and it is copyrighted even where OSHA reproduces it. A page that promised warm-up cycles would be promising something no public source provides. Set the schedule in your employer's plan and put the day's wind chill on the pre-task plan.

The National Weather Service states that bright sunshine can raise the wind chill temperature by 10 to 18 °F. That is why a sheltered sunny wall and an exposed deck on the same building are not the same job, and why the chart number is a planning value, not a measurement of what one worker feels.

No. Wind chill describes heat loss from exposed human skin. Wind does not cool an object below the air temperature; a pipe at 35 °F in a 40 mph wind still cannot freeze. It reaches air temperature faster, which is a different problem.

No, and this is where cold injuries actually start. OSHA's cold stress guidance notes that hypothermia can occur at air temperatures above 40 °F when a person is chilled by rain, sweat or immersion, and that trench foot can occur at temperatures as high as 60 °F if the feet stay wet. Wind chill is one input; wet clothing, workload and the length of the exposure are the others.

Sources & references

Content checked against these sources — last reviewed August 28, 2026.

By — Editorial team of SteelToeTools.com (published by LSEA SAS) Updated v1