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Weather Stations API Variables

This page lists the observation variables returned by the Weather Stations API (v2), grouped by category.

The variable names are self-describing: the physical quantity, aggregation method, and window are encoded in the name itself. For example, wind_speed_1min_mean is the 1-minute mean wind speed, wind_speed_10min_mean is the 10-minute mean, and rainfall_1h_sum is the total rainfall over the past hour. These names are used both as the field keys in the observation payload and as the accepted values for the variables query parameter.

Availability varies by station

Not all variables are available at all stations. The variables returned depend on the sensor equipment installed at each location. If you omit the variables query parameter, the API returns every variable available for that station.

Reading the fields
  • Units for every variable in a response are returned once in the top-level units block, so you never have to hard-code them.
  • All fields are nullable. A null value means no reading was received from the sensor at that timestamp — it does not mean zero.
  • Timestamps are right-closed window labels per WMO convention. A 10-minute mean labelled 10:10:00Z covers the period 10:00–10:10.
Migrating from the 1-Minute Observations API?

Every field name has changed. See the Legacy Migration guide for the full 1-Minute Observations → Weather Stations name map.

Metadata​

observation_time​

The ISO 8601 UTC timestamp of the observation window label — the time this observation represents, right-closed per WMO convention.

  • Unit: ISO 8601 UTC timestamp
  • Type: string
  • Example: "2026-06-11T12:00:00Z"

Air temperature​

air_temperature_1min_mean​

Air temperature averaged over 1 minute.

  • Unit: degC
  • Type: number (float)
  • Example: 15.6

air_temperature_1h_max​

Air temperature maximum over the past hour.

  • Unit: degC
  • Type: number (float)
  • Example: 16.2

air_temperature_1h_min​

Air temperature minimum over the past hour.

  • Unit: degC
  • Type: number (float)
  • Example: 11.8

dew_point_temperature_1min_mean​

Dew point temperature averaged over 1 minute.

  • Unit: degC
  • Type: number (float)
  • Example: 10.2

Wind​

wind_speed_1min_mean​

Wind speed averaged over 1 minute.

  • Unit: kn
  • Type: number (float)
  • Example: 12.5

wind_speed_10min_mean​

Wind speed averaged over 10 minutes.

  • Unit: kn
  • Type: number (float)
  • Example: 17.2

wind_speed_1h_mean​

Wind speed averaged over the past hour.

  • Unit: kn
  • Type: number (float)
  • Example: 11.8

wind_from_direction_1min_mean​

Wind from direction, measured clockwise from true north, averaged over 1 minute.

  • Unit: degrees_true
  • Type: integer
  • Example: 240

wind_from_direction_10min_mean​

Wind from direction, measured clockwise from true north, averaged over 10 minutes.

  • Unit: degrees_true
  • Type: integer
  • Example: 238

wind_from_direction_1h_mean​

Wind from direction, measured clockwise from true north, averaged over the past hour.

  • Unit: degrees_true
  • Type: integer
  • Example: 235

wind_gust_speed_1min_max​

Maximum wind gust speed over 1 minute.

  • Unit: kn
  • Type: number (float)
  • Example: 18.5

wind_gust_speed_10min_max​

Maximum wind gust speed over 10 minutes.

  • Unit: kn
  • Type: number (float)
  • Example: 24.0

wind_gust_speed_1h_max​

Maximum wind gust speed over the past hour.

  • Unit: kn
  • Type: number (float)
  • Example: 28.4

wind_gust_from_direction_1h​

Wind from direction at the time of the maximum gust over the past hour, measured clockwise from true north.

  • Unit: degrees_true
  • Type: integer
  • Example: 250

wind_gust_peak_time_1h​

Time of the maximum wind gust over the past hour.

  • Unit: ISO 8601 UTC timestamp
  • Type: string
  • Example: "2026-06-11T11:32:00Z"

wind_lull_speed_1min_min​

Minimum wind (lull) speed over 1 minute.

  • Unit: kn
  • Type: number (float)
  • Example: 8.3

wind_lull_speed_10min_min​

Minimum wind (lull) speed over 10 minutes.

  • Unit: kn
  • Type: number (float)
  • Example: 6.1

wind_run_1h_sum​

The distance travelled by the wind: mean wind speed multiplied by the period it was measured over. Wind run over an hour and mean wind speed over an hour are the same quantity in different unit systems.

  • Unit: m
  • Type: number (float)
  • Example: 22224.5

Pressure​

sea_level_pressure_1min_mean​

Air pressure corrected to mean sea level, averaged over 1 minute.

  • Unit: hPa
  • Type: number (float)
  • Example: 1013.2

sea_level_pressure_1h_max​

Maximum air pressure, corrected to mean sea level, over the past hour.

  • Unit: hPa
  • Type: number (float)
  • Example: 1014.0

sea_level_pressure_1h_min​

Minimum air pressure, corrected to mean sea level, over the past hour.

  • Unit: hPa
  • Type: number (float)
  • Example: 1012.1

Humidity​

relative_humidity_1min_mean​

Relative humidity averaged over 1 minute.

  • Unit: %
  • Type: number (float)
  • Example: 78.5

relative_humidity_1h_max​

Maximum relative humidity over the past hour.

  • Unit: %
  • Type: number (float)
  • Example: 82.0

relative_humidity_1h_min​

Minimum relative humidity over the past hour.

  • Unit: %
  • Type: number (float)
  • Example: 74.3

Precipitation​

rainfall_1min_sum​

Rainfall accumulated over 1 minute.

  • Unit: mm
  • Type: number (float)
  • Example: 0.2

rainfall_10min_sum​

Rainfall accumulated over 10 minutes.

  • Unit: mm
  • Type: number (float)
  • Example: 1.0

rainfall_1h_sum​

Rainfall accumulated over the past hour.

  • Unit: mm
  • Type: number (float)
  • Example: 1.4

rainfall_rate_10min_max​

Largest rainfall in any single minute during the past 10 minutes, in mm per minute.

  • Unit: mm/min
  • Type: number (float)
  • Example: 0.2

rainfall_rate_1h_max​

Largest rainfall in any single minute during the past hour, in mm per minute.

  • Unit: mm/min
  • Type: number (float)
  • Example: 0.2

Soil​

soil_temperature_5cm_1min_mean​

Soil temperature at 5 cm depth averaged over 1 minute.

  • Unit: degC
  • Type: number (float)
  • Example: 14.1

soil_temperature_10cm_1min_mean​

Soil temperature at 10 cm depth averaged over 1 minute.

  • Unit: degC
  • Type: number (float)
  • Example: 13.8

soil_temperature_20cm_1min_mean​

Soil temperature at 20 cm depth averaged over 1 minute.

  • Unit: degC
  • Type: number (float)
  • Example: 13.5

soil_temperature_50cm_1min_mean​

Soil temperature at 50 cm depth averaged over 1 minute.

  • Unit: degC
  • Type: number (float)
  • Example: 13.0

soil_temperature_1m_1min_mean​

Soil temperature at 1 m depth averaged over 1 minute.

  • Unit: degC
  • Type: number (float)
  • Example: 12.4

soil_moisture_1min_mean​

Volumetric soil moisture content averaged over 1 minute.

  • Unit: %
  • Type: number (float)
  • Example: 32.5

Solar radiation​

solar_irradiance_1min_mean​

Solar irradiance averaged over 1 minute.

  • Unit: W/m^2
  • Type: number (float)
  • Example: 450

solar_irradiance_1min_sum​

Solar irradiance integrated over 1 minute.

  • Unit: MJ/m^2
  • Type: number (float)
  • Example: 0.027

solar_irradiance_10min_sum​

Solar irradiance integrated over 10 minutes.

  • Unit: MJ/m^2
  • Type: number (float)
  • Example: 0.27

solar_irradiance_1h_sum​

Solar irradiance integrated over the past hour.

  • Unit: MJ/m^2
  • Type: number (float)
  • Example: 1.62

Visibility​

visibility_1min_mean​

Horizontal visibility averaged over 1 minute.

  • Unit: m
  • Type: integer
  • Example: 10000

visibility_10min_mean​

Horizontal visibility averaged over 10 minutes.

  • Unit: m
  • Type: integer
  • Example: 18500

Cloud​

Cloud is reported in up to three layers, ordered from lowest (layer 1) to highest (layer 3). Each layer is averaged over 30 minutes.

cloud_fraction_layer_1_30min_mean​

Cloud area fraction of the lowest cloud layer, averaged over 30 minutes.

  • Unit: okta
  • Type: integer
  • Example: 4

cloud_height_layer_1_30min_mean​

Base height of the lowest cloud layer, averaged over 30 minutes.

  • Unit: ft
  • Type: integer
  • Example: 4900

cloud_fraction_layer_2_30min_mean​

Cloud area fraction of the second cloud layer, averaged over 30 minutes.

  • Unit: okta
  • Type: integer
  • Example: 6

cloud_height_layer_2_30min_mean​

Base height of the second cloud layer, averaged over 30 minutes.

  • Unit: ft
  • Type: integer
  • Example: 9800

cloud_fraction_layer_3_30min_mean​

Cloud area fraction of the third cloud layer, averaged over 30 minutes.

  • Unit: okta
  • Type: integer
  • Example: 8

cloud_height_layer_3_30min_mean​

Base height of the third cloud layer, averaged over 30 minutes.

  • Unit: ft
  • Type: integer
  • Example: 19700

Other​

snow_depth_1min_mean​

Snow depth at the surface averaged over 1 minute.

  • Unit: m
  • Type: number (float)
  • Example: 0.1

Road weather variables​

Road weather variables are entitlement-gated. They are not part of the selectable variables list and cannot be requested via the variables parameter.

If your API key has road-sensor access, these variables are returned automatically for stations equipped with road sensors, and their names and units appear in the top-level units block of the response. Keys without the entitlement will not receive them.

They are documented here so that roading consumers can plan integrations ahead of provisioning.

Proposed for round 1 review

The road variable names below are proposed as part of this feedback round and are subject to change before general availability. Please review the names, units, and semantics against your existing road-sensor integrations.

road_surface_temperature_1min_mean​

Road surface temperature averaged over 1 minute.

  • Unit: degC
  • Type: number (float)
  • Example: 12.4

road_surface_state​

Categorical road surface condition sampled at the observation time (for example dry, wet, ice, snow).

  • Unit: category
  • Type: string
  • Example: "wet"

road_water_film_height_1min_mean​

Water film height on the road surface averaged over 1 minute.

  • Unit: mm
  • Type: number (float)
  • Example: 0.01

road_freezing_temperature_1min_mean​

Freezing point of water on the road surface (depressed by de-icing salt) averaged over 1 minute.

  • Unit: degC
  • Type: number (float)
  • Example: -2.1

road_friction_1min_mean​

Normalised road friction/grip index (0–1) averaged over 1 minute.

  • Unit: 0–1 (dimensionless)
  • Type: number (float)
  • Example: 0.82

road_ice_frequency_1min_mean​

Road black-ice sensor frequency averaged over 1 minute.

  • Unit: Hz
  • Type: number (float)
  • Example: 12.5

road_salt_concentration_1min_mean​

Road de-icing salt concentration averaged over 1 minute.

  • Unit: %
  • Type: number (float)
  • Example: 5.5

road_subsurface_temperature_2cm_1min_mean​

Road temperature 2 cm below the surface averaged over 1 minute.

  • Unit: degC
  • Type: number (float)
  • Example: 13.9

road_subsurface_temperature_5cm_1min_mean​

Road temperature 5 cm below the surface averaged over 1 minute.

  • Unit: degC
  • Type: number (float)
  • Example: 14.1

road_subsurface_temperature_30cm_1min_mean​

Road temperature 30 cm below the surface averaged over 1 minute.

  • Unit: degC
  • Type: number (float)
  • Example: 14.3

Technical reference​

For request parameters, response schemas, and a live try-it console, see the Weather Stations API v2 — Technical Reference. You can also download the OpenAPI specification.

If you're migrating from the legacy 1-Minute Observations API, see the Legacy Migration guide.