OneTool

Heat Index & Wind Chill Calculator

Feels-like temperature from humidity (heat index) or wind (wind chill).

Mode
Temperature unit

Heat index (feels like)

105.9°F

This is an informational estimate using standard NOAA/NWS formulas — not a weather forecast or official warning. For safety-critical decisions, consult official NWS heat or cold-weather advisories for your area.

What is this tool?

Heat index and wind chill both estimate how temperature actually feels given humidity or wind, using the standard NOAA/NWS formulas: the Rothfusz regression for heat index and the NWS 2001 formula for wind chill. Each formula is only meaningful in its intended range (heat index roughly 80°F+/40%+ RH, wind chill 50°F and below with 3+ mph wind) — outside that range this tool shows a clear caveat instead of a distorted number.

How to use it

  1. Choose Heat Index or Wind Chill.
  2. Enter temperature, and humidity or wind speed.
  3. Read the feels-like temperature — a caveat appears if the formula's range doesn't apply.