---
title: "Wind Chill Calculator (°F and °C) | Hilltop Cove"
description: "Work out the wind chill from air temperature and wind speed with the NWS and Environment Canada formula, in °F or °C, plus frostbite risk and times."
url: https://hilltopcove.top/
---

# Wind chill calculator

Enter the air temperature and the wind speed from your forecast. You get the wind chill in °F and °C, how fast exposed skin could freeze, and how the number changes as the wind picks up.

## How wind chill is calculated

Wind chill estimates how cold it feels on exposed skin when wind carries heat away. Since 2001 the US National Weather Service and the Meteorological Service of Canada have used the same index, developed by a joint group of meteorologists and researchers and checked in clinical trials. In US units it reads:

Wind chill (°F) = 35.74 + 0.6215T − 35.75V0.16 + 0.4275TV0.16

where T is the air temperature in °F and V the wind speed in mph. For °C, km/h, m/s or knots the calculator converts to °F and mph first, as the NWS calculation sheet does, then converts the answer back. Every value on the NWS wind chill chart comes out the same here.

## When it applies, and frostbite times

The NWS defines wind chill only at or below 50°F (10°C) and for winds above 3 mph (4.8 km/h); outside that range the tool shows no value. The risk levels and freezing times come from Environment and Climate Change Canada, by the wind chill in °C: from −28 exposed skin can freeze in 10 to 30 minutes, from −40 in 5 to 10, from −48 in 2 to 5, and at −55 or colder in under 2 minutes. Canada adds that frostbite can come faster in sustained winds over 50 km/h. Frostbite needs the air itself to be below freezing; above that, wind still speeds up heat loss.

## Sources

- National Weather Service. [Wind Chill Chart](https://www.weather.gov/safety/cold-wind-chill-chart) and FAQ.
- National Weather Service. [Wind Chill](https://www.weather.gov/media/lsx/wcm/Winter2008/Wind_Chill.pdf) (history of the 2001 JAG/TI index, St. Louis office).
- National Weather Service. [Wind Chill calculation sheet](https://www.weather.gov/media/epz/wxcalc/windChill.pdf).
- Environment and Climate Change Canada. [Wind chill and the Wind Chill Index](https://www.canada.ca/en/services/environment/weather/severeweather/wind-chill-index.html).
- NIST Special Publication 811, [Appendix B.9: conversion factors](https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b9) (temperature and speed).

## More weather tools

Every tool shows °F and °C, remembers your units, and names the formula and source it uses.

- [Heat index calculator](https://hilltopcove.top/heat-index-calculator/): How hot humid air feels, using the NWS formula, with the NWS caution and danger levels.
- [Feels-like temperature](https://hilltopcove.top/feels-like-temperature/): One number for how it feels, using wind chill or heat index where each applies.
- [Beaufort scale](https://hilltopcove.top/beaufort-scale/): Forces 0 to 12 with speeds in knots, km/h, mph and m/s, and what you see at sea and on land.
- [Wind speed converter](https://hilltopcove.top/wind-speed-converter/): Convert between mph, km/h, m/s, knots, ft/s and Beaufort force in one go.

## Recommended

Two free tools from elsewhere for planning a day outdoors online.

### A spare inbox for trail sign-ups

Booking a one-off guided walk, or downloading a route map that wants your email first? CleanTempMail gives you a temporary address in a click, with no account, and deletes the messages after three days.

[Get a temporary address](https://cleantempmail.com/)

### Check a gear shop before you pay

Found a cheap weather station or waterproof jacket on a site you do not know? WebTraceCheck's free website audit looks over a shop's pages and setup before you hand over your card details.

[Audit a shop's website](https://webtracecheck.com/website-audit)

## Questions

**Can wind chill freeze water or my car's radiator?**

No. Wind only cools objects faster down to the air temperature, never below it. Water freezes at 32°F (0°C) whatever the wind chill.

**Why does Canada start at 0°C when the NWS goes up to 50°F?**

Both use the same formula. Environment Canada only reports wind chill at 0°C or below with wind of 5 km/h or more, while the NWS defines it up to 50°F. The calculator shows a value for the NWS range.

**Which wind speed should I enter?**

The one in your forecast or from a weather station. The NWS index is built for winds measured at the standard height of 33 feet (10 m) and adjusts them to face height itself. If gusts are forecast, try the higher number too to see the worse case.