- Wind chill
- 8.85 °F
How it works
Pipes do not reach wind chill
Wind speeds an object’s cooling toward air temperature; wind chill alone does not cool it below that temperature. Use measured air temperature when interpreting freezing conditions for pipes, rather than substituting the apparent-cold index.
Reading the conditions behind wind chill
Wind chill combines air temperature and wind under the reference method's stated conditions. Check that both values fall within the formula's intended range and that wind-speed units are correct. The result is an apparent-temperature index rather than a change in the measured air temperature. It does not determine a safe outdoor exposure time for a particular person.
Wind chill: formula and assumptions
Wind chill(°F) = 35.74 + 0.6215T − 35.75V^0.16 + 0.4275TV^0.16.
The formula applies to temperatures at or below 50°F and wind above 3 mph.
Wind chill with independent units: formula and assumptions
Wind chill °F = 35.74 + 0.6215T − 35.75V^0.16 + 0.4275TV^0.16.
The NWS equation applies at or below 50°F and above 3 mph. Inputs are converted before checking those limits.
Worked example
Using the Wind chill example:
- Air temperature (°F)
- 20
- Wind speed (mph)
- 10
Wind chill(°F) = 35.74 + 0.6215T − 35.75V^0.16 + 0.4275TV^0.16.
Example result
Wind chill: 8.85 °F
These are illustrative inputs. Change the values to explore a different scenario.
Formula references
References explain the underlying methods; they do not imply endorsement or individual professional review of Finflo.
Common questions
Why is the calculation restricted to cold and windy conditions?
The stated NWS formula has a defined validity range. Applying it to warmer temperatures or insufficient wind would misrepresent the model.
Is wind chill a replacement for the measured air temperature?
No. It is an apparent-cold estimate under the model, not a change to the thermometer's air-temperature reading.
Prepared by Finflo. See our methodology and editorial policy.