is an option for functions like AirTemperatureData that determines the units of the result.


  • The following settings for UnitSystem can be used:
  • "Imperial"return results in imperial units
    "Metric"return results in metric units
  • Specific units depend on the function and property used.
  • The default setting for UnitSystem is determined by your $GeoLocation and can be reset by adjusting $UnitSystem.


open allclose all

Basic Examples  (1)

Control whether results are returned in metric or imperial units:

Changing units can also be accomplished with UnitConvert:

Properties & Relations  (2)

Quantities returned for station properties can be adjusted with UnitSystem:

The default value is determined by $UnitSystem, which is set by your computer's location:

Possible Issues  (2)

WindDirectionData does not return basic results in metric or imperial units:

Improper settings for UnitSystem are ignored:

Introduced in 2014