metpy.calc.apparent_temperature(temperature, relative_humidity, speed, face_level_winds=False, mask_undefined=True)[source]

Calculate the current apparent temperature.

Calculates the current apparent temperature based on the wind chill or heat index as appropriate for the current conditions. Follows [NWS10201].

  • temperature (pint.Quantity) – Air temperature

  • relative_humidity (pint.Quantity) – Relative humidity expressed as a unitless ratio in the range [0, 1]. Can also pass a percentage if proper units are attached.

  • speed (pint.Quantity) – Wind speed at 10m. If instead the winds are at face level, face_level_winds should be set to True and the 1.5 multiplicative correction will be applied automatically.

  • face_level_winds (bool, optional) – A flag indicating whether the wind speeds were measured at facial level instead of 10m, thus requiring a correction. Defaults to False.

  • mask_undefined (bool, optional) – A flag indicating whether a masked array should be returned with values where wind chill or heat_index is undefined masked. For wind chill, these are values where the temperature > 50F or wind speed <= 3 miles per hour. For heat index, these are values where the temperature < 80F. Defaults to True.


pint.Quantity – Corresponding apparent temperature value(s)

Changed in version 1.0: Renamed rh parameter to relative_humidity

See also

heat_index, windchill