Parameters

name	unit	type	precision	description	notes
sunrise	UTC	string	2	UTC time of sunrise for this station on the valid date.	Not directly observed - derived from the station position.
precipAcc12Hour	mm	float	2	Amount of liquid precipitation (typically rain) measured in the 12 hours before the valid timestamp.	None
precipAcc6Hour	mm	float	2	Amount of liquid precipitation (typically rain) measured in the 6 hours before the valid timestamp.	None
metarWx	code	code	2	Plain English description of present weather conditions derived directly from METAR code.	Example: ‘+TS’ in original METAR would be expressed as ‘heavy thunderstorm’
precipType		string	2	Currently in beta.	None
snowDepth	mm	float	2	The measure of accumulated snow thickness on the ground surface in millimeters.	This is total snow depth at a given time, not freshly added snow over a period.
waterLevel	mm	float	2	None	None
windGust2m	m/s	float	2	Wind gust speed 2m above the surface, normally a 3 second average sampled in the 10 minute before the valid timestamp.	This height is an approximation for data sources where we know or it is reasonable to assume that winds will be measured closer to 2m than 10m. As a general rule 10m wind speeds will be 30% higher than 2m.
airTempMax24Hour	Celsius	float	1	Maximum air temperature 2m above the surface, measured in the 24 hours before the valid time.	Can be reported at source or aggregated by our API over any daily period by specifying interval=24h in observations endpoint.
altimeter	hpa	float	2	Air pressure corrected to / valid at mean sea level for the purpose of aircraft instrument calibration.	Roughly equivalent to pressureMsl but will start to deviate significantly at higher elevations (>1km)
visibility	km	float	2	Horizontal visibility.	Maximum visibility value may vary depending on source.
sunshine60Min	minutes	integer	None	Number of minutes of sunshine (sun unobscured by cloud) over the hour before the observation time.	None
precipRate	mm/hr	float	2	Precipitation rate or intensity, in mm per hour.	Can be effectively taken as precipAcc60Min (mm) assuming the precip at observed time was constant over the previous hour. If precipRate is given every 10 minutes, divide by 6 to get precipAcc10Min equivalent.
cloudBase	m	float	1	The observed altitude of the base of the clouds, aka ceiling height.	When we talk about a cloud base of 3,000 ft, we usually mean that there is broken or more cloud from 3,000 ft.
airTempMin1Hour	Celsius	float	1	Minimum air temperature 2m above the surface, measured in the 1 hour before the valid time.	Reported at source. We do not currently aggregate data from lower time periods to higher time periods.
windGust	m/s	float	2	Wind gust speed 10m above the surface, normally a 3 second average sampled in the 10 minute before the valid timestamp.	Exact height of measurement is 10m for networks which conform to WMO standards (METAR and SYNOP).
airTempMax12Hour	Celsius	float	1	Maximum air temperature 2m above the surface, measured in the 12 hours before the valid time.	Reported at source. We do not currently aggregate data from lower time periods to higher time periods.
sunshine24Hour	minutes	integer	None	Number of minutes of sunshine (sun unobscured by cloud) over the 24 hours before the observation time.	None
airTempMin12Hour	Celsius	float	1	Minimum air temperature 2m above the surface, measured in the 12 hours before the valid time.	Reported at source. We do not currently aggregate data from lower time periods to higher time periods.
airTempMin24Hour	Celsius	float	1	Minimum air temperature 2m above the surface, measured in the 24 hours before the valid time.	Can be reported at source or aggregated by our API over any daily period by specifying interval=24h in observations endpoint.
windSpeed2m	m/s	float	2	Wind speed 2m above the surface, normally averaged over 10 minutes.	This height is an approximation for data sources where we know or it is reasonable to assume that winds will be measured closer to 2m than 10m. As a general rule 10m wind speeds will be 30% higher than 2m.
windDirection2m	degree	float	2	Compass direction the corresponding windSpeed2m is coming from.	This height is an approximation for data sources where we know or it is reasonable to assume that winds will be measured closer to 2m than 10m. As a general rule 10m wind speeds will be 30% higher than 2m.
airTemp5cm	Celsius	float	1	Temperature measured near the ground at a height of 5 centimetres.	Available predominately via DTN EU network
sunset	UTC	string	2	UTC time of sunset for this station on the valid date.	Not directly observed - derived from the station position.
airTemp	Celsius	float	1	Instantaneous air temperature 2m above the surface.	Exact height of measurement is 2m for networks which conform to WMO standards (Metar and Synop). This cannot be guaranteed for all sources but deviations in air temperatures at most surface measurement heights will be trivial.
cloudCover	percent	float	2	Percentage of the sky covered by cloud. 100% = overcast, 0% = blue sky.	Not to be confused with ‘effective cloud cover’. Sky can still be bright with 100% totalCloud if cloud is high/thin. For Metars this parameter is derived from given cloud groups (SCT/BKN etc.) therefore has limited precision. Multiply by 0.08 to convert to oktas.
precipAcc10Min	mm	float	2	Amount of liquid precipitation (typically rain) measured in the 10 minutes before the valid timestamp.	None
soilMoisture	percent	float	2	The moisture level of the soil.	Stations may have multiple sensors and depths, currently the api exposes the deepest value available. In future multiple depths and sensors will be supported.
metarSky	code	string	None	Raw METAR code describing cloud cover, height and type - used for aviation purposes.	Example: FEW005 SCT010CB BKN025 means 'few at five hundred feet, scattered cumulonimbus at one thousand feet, broken at two thousand five hundred feet'. Up to three, but occasionally more, cloud groups may be reported. Further decoding information is widely available online.
wbgt	Celsius	float	1	Wet Bulb Globe Temperature (WBGT) is a measure of the heat stress in direct sunlight, which takes into account: temperature, humidity, wind speed, sun angle and cloud cover (solar radiation).	None
surfaceTemp	Celsius	float	1	Temperature of the road (pavement) surface, usually used for winter road maintenance.	RWIS stations often have multiple sensors, where a station has more than 1 these are labelled as surfaceTemp2 to surfaceTemp6. surfaceTemp is not exclusive to networkType RWIS, other networkTypes may have this parameter.
soilTemp	Celsius	float	1	Temperature of soil at a given depth.	Stations may have multiple sensors and depths, currently the api exposes the deepest value available. In future multiple depths and sensors will be supported.
shortWaveRadiation	watts per square meter	float	2	Instantaneous solar (direct plus diffuse) radiation. Also called GHI.	This can be effectively converted to globalRadiation60Min (Jcm2) by multiplying by 0.36, assuming the solarRadiation at observed time was constant over the previous hour.
dewPoint	Celsius	float	1	Dew point temperature 2m above the surface. The temperature to which the air must be cooled for saturation and condensation to occur.	Exact height of measurement is 2m for networks which conform to WMO standards (Metar and Synop). This cannot be guaranteed for all sources but deviations in air temperatures at most surface measurement heights will be trivial.
relativeHumidity	percent	float	2	Relative humidity represents the ratio of the actual amount of water vapour in the air to the maximum amount that can physically exist at a given air temperature.	Exact height of measurement is 2m for networks which conform to WMO standards (Metar and Synop). This cannot be guaranteed for all sources but deviations in air temperatures at most surface measurement heights will be trivial.
mslPressure	hPA	float	2	Air pressure corrected to / valid at mean sea level.	Roughly equivalent to altimeter but will start to deviate significantly at higher elevations (>1km)
stationPressure	hPA	float	2	Air pressure valid at station’s elevation.	None
windSpeed	m/s	float	2	Wind speed 10m above the surface averaged over 10 minutes.	Exact height of measurement is 10m for networks which conform to WMO standards (METAR and SYNOP).
windDirection	degree	float	2	Compass direction the corresponding windSpeed10m is coming from.	Exact height of measurement is 10m for networks which conform to WMO standards (METAR and SYNOP).
precipAcc60Min	mm	float	2	Amount of liquid precipitation (typically rain) measured in the 1 hour before the valid timestamp.	We do not currently sum or aggregate from sub-hourly precipitation to get to precip60Min but this is often done at source. The parameter ‘precip’ is a value for accumulated precipitation and may also be useful although its exact definition depends on its source.
waveDirection	degrees	float	None	The mean direction of ocean/sea surface waves generated by local winds and swell.	None
precipAcc24Hour	mm	float	2	Amount of liquid precipitation (typically rain) measured in the 24 hours before the valid timestamp.	Can be reported at source or aggregated by our API over any daily period by specifying interval=24h in observations endpoint. Values from NOAA_GHCND are stored with default timestamp 1111UTC where the true timestamp is not known.
seaWaterTemperature	Celsius	float	2	The temperature of the water close to the ocean’s surface.	None
wavePeakPeriod	seconds	float	2	The period of the most energetic waves where period is the time it takes for two consecutive wave crests, on the surface of the ocean/sea, to pass through a fixed point.	None
sunshine10Min	minutes	float	None	Number of minutes of sunshine (sun unobscured by cloud) over the 10 minutes before the observation time.	None
seaWaterSalinity	g/kg	float	2	The salt concentration in sea water.	None
eastwardCurrent	m/s	float	None	The speed of the component of the sea current travelling towards the east. Negative is westerly.	None
northwardCurrent	m/s	float	None	The speed of the component of the sea current travelling towards the north. Negative is southerly.	None
significantWaveHeight	metres	float	2	The mean wave height (trough to crest) of the highest third of the waves.	None
precipAcc3Hour	mm	float	2	Amount of liquid precipitation (typically rain) measured in the 3 hours before the valid timestamp.	None
windGust3Hour	m/s	float	2	Maximum observed wind gust speed 10m above the surface during the 3 hours before the valid timestamp.	Exact height of measurement is 10m for networks which conform to WMO standards (METAR and SYNOP).
windGust6Hour	m/s	float	None	Maximum observed wind gust speed 10m above the surface during the 6 hours before the valid timestamp.	Exact height of measurement is 10m for networks which conform to WMO standards (METAR and SYNOP).
globalRadiation60Min	joules per square centimeter	float	None	Solar radiation integrated over the previous hour.	This can be effectively converted to the instantaneous solarRadiation by dividing by 0.36, assuming the radiation at the end of the hour = the average of the previous hour.
leafWetness	index	float	2	Presence of surface moisture on a crop.	With range from 0 (completely dry) to 15 (saturated).
globalRadiation24Hour	joules per square centimeter	float	None	Total solar radiation accumulated over the past 24 hours.	Can be reported at source or aggregated by our API over any daily period by specifying interval=24h in observations endpoint.
wmoWeatherCode	code	integer	0	WMO weather code corresponding to table 4677.	See reference table on https://www.nodc.noaa.gov/archive/arc0021/0002199/1.1/data/0-data/HTML/WMO-CODE/WMO4677.HTM
airTempMax1Hour	Celsius	float	1	Maximum air temperature 2m above the surface, measured in the 1 hour before the valid time.	Reported at source. We do not currently aggregate data from lower time periods to higher time periods.
windGust60Min	m/s	float	2	Maximum observed wind gust speed 10m above the surface during the 1 hour before the valid timestamp.	Exact height of measurement is 10m for networks which conform to WMO standards (METAR and SYNOP).
wmoWeatherCode4680	code	integer	0	WMO weather code corresponding to table 4680.	Limited availability, use wmoWeatherCode in most cases.
feelsLikeTemp	Celsius	float	2	The equivalent human perceived temperature, taking into account the combined effects of air temperature, relative humidity and wind speed.	When airTemp is less than or equal to 10 celsius, feelsLikeTemp is synonymous with windChill. If airTemp is great than or equal to 27, its synonymous with heatIndex.
wetBulb	Celsius	float	1	The temperature read by a well-ventilated thermometer covered in water-soaked cloth.	At 100% relative humidity, the wet-bulb temperature is equal to the air temperature; at lower humidity the wet-bulb temperature is lower than dry-bulb temperature because of evaporative cooling.
airTempAvg24Hour	Celsius	float	1	Air temperature 2m above the surface, averaged over the 24 hours before the valid time	None
windSpeedAvg24Hour	m/s	float	2	Wind speed 10m above the surface, averaged over the 24 hours before the valid time	None
windGustMax24Hour	m/s	float	2	Maximum wind gust speed 10m above the surface, observed in the 24 hours before the valid time.	None
windDirectionAvg24Hour	degree	float	2	Wind direction averaged over the 24 hours before the valid time	None
surfaceTemp4	Celsius	float	1	Temperature of the road (pavement) surface, usually used for winter road maintenance.	RWIS stations often have multiple sensors, where a station has more than 1 these are labelled as surfaceTemp2 to surfaceTemp6. surfaceTemp is not exclusive to networkType RWIS, other networkTypes may have this parameter.
surfaceTemp6	Celsius	float	1	Temperature of the road (pavement) surface, usually used for winter road maintenance.	RWIS stations often have multiple sensors, where a station has more than 1 these are labelled as surfaceTemp2 to surfaceTemp6. surfaceTemp is not exclusive to networkType RWIS, other networkTypes may have this parameter.
soilTemp100cm	Celsius	float	1	Temperature of the ground 1 metre below the surface.	None
surfaceTemp3	Celsius	float	1	Temperature of the road (pavement) surface, usually used for winter road maintenance.	RWIS stations often have multiple sensors, where a station has more than 1 these are labelled as surfaceTemp2 to surfaceTemp6. surfaceTemp is not exclusive to networkType RWIS, other networkTypes may have this parameter.
fuelMoisture	percent	float	2	Fuel moisture is a measure of the amount of water in a fuel (vegetation) available to a fire
pressureChange3Hour	hPA	float	2	The change in air pressure over a 3-hour period.	This parameter provides information on the change in air pressure over a 3-hour interval, which can be useful for weather forecasting and analysis.
surfaceTemp2	Celsius	float	1	Temperature of the road (pavement) surface, usually used for winter road maintenance.	RWIS stations often have multiple sensors, where a station has more than 1 these are labelled as surfaceTemp2 to surfaceTemp6. surfaceTemp is not exclusive to networkType RWIS, other networkTypes may have this parameter.
surfaceTemp5	Celsius	float	1	Temperature of the road (pavement) surface, usually used for winter road maintenance.	RWIS stations often have multiple sensors, where a station has more than 1 these are labelled as surfaceTemp2 to surfaceTemp6. surfaceTemp is not exclusive to networkType RWIS, other networkTypes may have this parameter.
conductivity	mhos/cm	float	2	An RWIS parameter. Indicates the ability of the road surface to conduct electrical current, which can be useful for assessing the presence of moisture, salts, or other substances that affect road conditions.	None
precipAcc15min	mm	float	2		None
freshSnowDepth	mm	float	2	The newly added / fresh amount of of accumulated snow in millimeters, since the last observation.	This is freshly added snow, for total snow depth use snowDepth.
airTemp5cmMin12Hour	Celsius	float	None	Minimum temperature measured near the ground at a height of 5 centimetres, over the past 12 hours.