Unit groups and measurement units

The Weather API includes a unitGroup parameter that allows you to specify the units that will be used when returning weather data. This article describes the units within each group. The API uses four group ids to indicate the units that will be used – us, metric, uk and base.

us – United States

Weather Variable	Measurement Unit
Temperature, Heat Index & Wind Chill	Degrees Fahrenheit
Precipitation	Inches
Snow	Inches
Wind & Wind Gust	Miles Per Hour
Visibility	Miles
Pressure	Millibars
Solar Radiation	W/m2
Solar Energy	MJ/m2

metric – Metric

Weather Variable	Measurement Unit
Temperature, Heat Index & Wind Chill	Degrees Celcius
Precipitation	Millimeters
Snow	Centimeters
Wind & Wind Gust	Kilometers Per Hour
Visibility	Kilometers
Pressure	Millibars (Hectopascals)
Solar Radiation	W/m2
Solar Energy	MJ/m2

uk – United Kingdom

Weather Variable	Measurement Unit
Temperature, Heat Index & Wind Chill	Degrees Celcius
Precipitation	Millimeters
Snow	Centimeters
Wind & Wind Gust	Miles Per Hour
Visibility	Miles
Pressure	Millibars
Solar Radiation	W/m2
Solar Energy	MJ/m2

base – Base or scientific units

Weather Variable	Measurement Unit
Temperature, Heat Index & Wind Chill	Kelvin
Precipitation	Millimeters
Snow	Centimeters
Wind & Wind Gust	Meters Per Second
Visibility	Kilometers
Pressure	Millibars
Solar Radiation	W/m2
Solar Energy	MJ/m2