The Visual Crossing Weather Data platform provides the ability to easily access weather data sets including weather forecast data, weather history data and historical weather summary data. The data is available for download through the Weather Data Query Page and the Timeline Weather API.
Core weather elements
These columns are common to most weather data sets unless disabled. Advanced weather elements are also available including agricultural and energy elements.
| Element | Description | US | metric | UK |
|---|---|---|---|---|
| Core Weather Elements | ||||
| tempmax | Maximum Temperature | F | C | C |
| tempmin | Minimum Temperature | F | C | C |
| temp | Temperature (or mean temperature) | F | C | C |
| dew | Dew Point | F | C | C |
| feelslikemax | Maximum Feels like | F | C | C |
| feelslikemin | Maximum Feels like | F | C | C |
| feelslike | Feels like | F | C | C |
| precip | Precipitation | inches | mm | mm |
| precipprob | Precipitation chance | % | % | % |
| precipcover | Precipitation Cover | % | % | % |
| preciptype | Precipitation type | – | – | – |
| snow | Snow | inches | cm | cm |
| snowdepth | Snow Depth | inches | cm | cm |
| windspeed | Wind Speed | mph | kph | kph |
| windgust | Wind Gust | mph | kph | kph |
| winddir | Wind Direction | degrees | degrees | degrees |
| visibility | Visibility | miles | km | km |
| cloudcover | Cloud Cover | % | % | % |
| humidity | Relative Humidity | % | % | % |
| pressure | Sea Level Pressure | mb | mb | mb |
| solarradiation | Solar Radiation | W/m2 | W/m2 | W/m2 |
| solarenergy | Solar Energy | MJ/m2 | MJ/m2 | MJ/m2 |
| uvindex | UV Index | – | – | – |
| severerisk | Severe Risk | – | – | – |
| sunrise | Sunrise time | – | – | – |
| sunset | Sunset time | – | – | – |
| moonphase | Moonphase | – | – | – |
| icon | A weather icon | – | – | – |
| conditions | Short text about the weather | – | – | – |
| description | Description of the weather for the day | – | – | – |
| stations | List of weather stations sources | – | – | – |
Temperature (temp, tempmax, tempmin)
There are three main columns for indicating temperature – Minimum Temperature, Maximum Temperature and Temperature. These will return data in Fahrenheit, Celsius or Kelvin depending on the unit group. The three temperature columns indicate the minimum, maximum and average (mean) temperature for the time period in question. For example, if you request daily data then you will receive the data for minimum, maximum and mean temperature for each day. If you request data for the shortest available timeframe for that request (typically one hour), the minimum, maximum and mean are returned with the same value. All data sets will include all three columns even if the values are the same to ease consumption of the data sets and keep data set consistency.
Wind (wspd, wdir, wgust)
Wind data includes wind speed, wind gust and wind direction.
Wind speed and wind direction (wspd, wdir)
The wind speed and wind direction indicate the wind speed for the location and time period requested. The hourly speed and direction values are the average (mean) of the speed and direction for the two minutes prior to the measurement being record. Daily and other time period values display the maximum of the hourly values. In the Timeline Weather API, the mean and minimum daily windspeed values are also available.
The units of the data will be in miles per hour, kilometers per hour or m/s depending on the unit group.
Wind speed is typically measured 10m above ground in a location with no nearby obstructions.
The wind direction indicates the direction from where the wind is blowing from. The units of the wind direction is degrees from north. The value ranges from 0 degrees (from the North), to 90 degrees (from the east), 180 degrees (from the south), 270 (from the west) back to 360 degrees.
Wind gust (wgust)
Wind gust is the maximum wind speed measures over a short amount of time (typically less than 20 seconds). Note that a wind gust requires the measured short term wind speed to be significantly more than mean wind speed. Typically, the wind speed should be 10 knots more (11mph or 18kph). When the wind gust does not meet these criteria, a null/empty value is returned.
The wind direction indicates the direction from where the wind is blowing from. The units of the wind direction is degrees from north. The value ranges from 0 degrees (from the North), to 90 degrees (from the east), 180 degrees (from the south), 270 (from the west) back to 360 degrees.
Precipitation (precip, precipchance and precipcover)
Precipitation is the sum of the amount of liquid equivalent rainfall, snow or other precipitation that fell is predicted to fall in the period. Three output variables cover precipitation:
Precipitation (precip)
The amount of precipitation that fell or is predicted to fall in the specified time period. The values are indicated in inches or mm.
Chance of precipitation (precipchance)
The possibility of precipitation for the given time period expressed as a percentage change from 0-100%. This applies to the forecast queries only.
Precipitation Coverage
This is the proportion of time for which measurable precipitation was recorded during the time period, expressed as a percentage. For example, if within a 24 hour day there are six hours of measurable rainfall, the precipitation coverage is 25% (6/24*100). This information is only available for historical weather observation data and historical summaries. Note that where as trace precipitation is considered zero value for the precipitation column, a trace precipitation report will be considered as precipitation for the precipitation coverage column. Therefore it is possible to observe zero reported precipitation with a non-zero precipitation coverage.
Precipitation Type (preciptype )
Provides the type(s) of precipitation expected. Possible values include rain, snow, freezing rain and ice.
Cloud cover (cloudcover)
Cloud cover is the amount of sky that is covered by cloud expressed as a percentage. The cloud coverage is for all altitudes. Daily values include the mean of the hourly cloud coverage values.
Snow and Snow Depth (snow, snowdepth)
Snow is the amount of new snow that has fallen in the time period. Snow depth is the average amount of snow currently on the ground for the time period. Snow depth will increase with additional snowfall and decrease with melting and compaction. Both snow and snow depth are expressed in inches or centimeters.
Relative Humidity, Feelslike, Heat Index and Wind Chill (humidity, heatindex, windchill)
Relative humidity (humidity)
Relative humidity is the amount of water vapor present in the air compared the maximum amount possible for a given temperature, expressed as a mean percentage. Human comfort levels are typically found between 30-70%. Values higher than 70% are considered humid. Values lower than 30% are considered dry.
Feelslike, Heat Index and Wind chill
Heat Index is a measure of how hot it feels combining the actual air temperature with the relative humidity. High humidity is associated with discomfort by making the apparent temperature hotter than it would otherwise feel. Values are expressed in the same units as temperature. Heat index values are only calculated when the temperature is greater than 80F (about 26.7C) and the relative humidity is greater than 40%. An empty value is returned outside of these ranges.
Wind chill is the measure of how cold it feels combining the actual air temperature with the wind speed. Wind makes temperatures feel colder than when the air is still. Values are expressed in the same units as temperature. Wind chill values are only calculated when the temperature is less than 50F (about 10C) and the wind speed is greater than 3mph (5kph). An empty value is returned outside of these ranges.
Temperature, heat index and wind chill are combined into a single ‘feelslike’ element for clarity and ease of use. The daily maximum (feelslikemax) and minimum (feelslikemin) are included in daily values. See What is the difference between temperature, heat index, wind chill, feels like temperature, apparent temperature and RealFeel Temperature? for more information.
Visibility
Visibility is the distance that can be seen in daylight. This accounts for weather phenomenon such as haze, mist, fog or smoke. The distance is expressed in miles or kilometers.
Sea Level Pressure (sealevelpressure)
The atmospheric pressure at a location that removes reduction in pressure due to the altitude of the location. This is expressed in millibars.
Solar radiation and energy
Solar radiation and solar energy are available in the forecast and historical observations datasets. The solar radiation measures the power (in W/m2) at the instantaneous moment of the observation (or forecast prediction). The solar energy (in MJ/m2 ) indicates the total energy from the sun that builds up over an hour or day. See the full solar radiation data documentation.
UV Index
A value between 0 and 10 indicating the level of ultra violet (UV) exposure for that hour or day. 10 represents high level of exposure, and 0 represents no exposure. The UV index is calculated based on amount of short wave solar radiation which in turn is a level the cloudiness, type of cloud, time of day, time of year and location altitude. Daily values represent the maximum value of the hourly values.
Weather Type (conditions)
Notable weather conditions reported at a particular location such as any thunderstorms, rainfall etc. The availability of this data is dependent on the weather station that observed the information and is not reported by all weather stations – the absence of a particular weather type should not be considered evidence that the weather type did not occur. Weather type is only available for historical datasets and relies on the weather stations providing the data.
See Weather Data Conditions for more information.
Astronomical information
Sunset & sunrise
The time of the sunrise and sunset for the date and location in question. Times are given in the local time zone.
Moonphase
A decimal value representing the current moon phase between 0 and 1 where 0 represents the new moon, 0.5 represents the full moon. The full cycle can be represented as:
- 0 – new moon
- 0-0.25 – waxing crescent
- 0.25 – first quarter
- 0.25-0.5 – waxing gibbous
- 0.5 – full moon
- 0.5-0.75 – waning gibbous
- 0.75 – last quarter
- 0.75 -1 – waning crescent
Air quality elements
AQI indices
Include aqius (U.S. EPA AQI) and aqieur (European AQI) to get single-number air-quality scores alongside your weather data. aqius is an integer that commonly spans 0 into the 300+ range, with values above 100 indicating unhealthy conditions, while aqieur ranges from 1 (very low) to 6 (extremely high). These indices summarize multiple pollutants and are available globally with limited history and a five-day forecast at hourly or daily resolution.
Elements: aqius, aqieur
Particulate matter
pm1, pm2p5, and pm10 report concentrations of particles with aerodynamic diameters less than 1 µm, 2.5 µm, and 10 µm, respectively—covering fine to coarse fractions from sources such as combustion, dust, and wildfire smoke. Use these alongside wind and humidity to study exposure, haze events, and mitigation triggers; they’re returned on the same hourly/daily cadence as the other air-quality fields.
Elements: pm1, pm2p5, pm10
Gaseous pollutants
o3 (ground-level ozone), no2, so2, and co provide near-surface pollutant concentrations that complement particulate data for compliance checks, health risk scoring, and operational decisions (e.g., changing work shifts or routing). Pair them with AQI indices or analyze directly to track specific emission signatures and short-term spikes
Elements: o3, no2, so2, co
Availability: Coverage is global with limited history and a five-day forecast at hourly or daily granularity.
Example:
&elements=datetime,pm1,pm2p5,pm10,o3,no2,so2,co,aqius,aqieurAgriculture elements
Soil and crop-focused fields include soil temperature at four standard depths (0–0.1 m, 0.1–0.4 m, 0.4–1.0 m, 1.0–2.0), soil moisture as both depth of water (mm/in) and volumetric fraction (0–1), reference evapotranspiration (et0, Penman–Monteith), and spray-planning metrics like wet-bulb temperature and delta-T. These elements are available at hourly resolution (with daily values derived by aggregation), follow the API’s unitGroup for units, and can be mixed with standard timeline variables for field operations, irrigation scheduling, and disease/pest models. Availability varies by location and plan level.
The timeline API provides degreedays and accdegreedays with multiple calculation methods (average, sine, double-sine, triangle, double-triangle) and full control over parameters, including a configurable base temperature (commonly 50°F/10°C), an optional max cap for growing degree accumulation, a season start date, and a temperature-based season reset. You can also invert the calculation to return heating degree days. This flexibility supports agriculture (GDD tracking), building energy analysis (HDD/CDD), and custom phenology models within a single query.
Degree days
Elements: degreedays, accdegreedays
Example
&elements=datetime,tempmax,tempmin,degreedays,accdegreedaysSoil temperature
Elements: soiltemp01 (0–0.1 m), soiltemp04 (0.1–0.4 m), soiltemp10 (0.4–1.0 m), soiltemp20 (1.0–2.0 m)
Temporal: hourly; daily values are the mean of hourly
Units: °C, °F, or K based on unitGroup
Availability: forecast and historical hourly from 2022‑04‑01 onward (coverage varies by location)
Example
&elements=datetime,temp,soiltemp01,soiltemp04,soiltemp10,soiltemp20Soil moisture
Elements: soilmoisture01, soilmoisture04, soilmoisture10, soilmoisture20
soilmoisturevol01, soilmoisturevol04, soilmoisturevol10, soilmoisturevol20
Temporal: hourly; daily values are the mean of hourly
Availability: forecast and historical hourly from 2022‑04‑01 onward (coverage varies)
Example
&elements=datetime,soilmoisture01,soilmoisture04,soilmoisture10,soilmoisture20,soilmoisturevol01,soilmoisturevol04,soilmoisturevol10,soilmoisturevol20Evapotranspiration
Element: et0
Method: Penman–Monteith
Temporal: hourly; daily values are the sum of hourly
Units: mm or inches based on unitGroup
Availability: forecast and historical
Example
&elements=datetime,et0Wet bulb and delta T
Elements: tempwet (wet‑bulb temperature), deltat (dry‑bulb minus wet‑bulb)
Units: same as temperature unit group
Example
&elements=datetime,temp,tempwet,deltatEnergy elements
Energy-oriented fields extend wind and solar detail for siting and production modeling. Wind speed and direction are available at 50 m, 80 m, and 100 m above ground to better match turbine hub heights, while solar adds direct normal (DNI), diffuse, global horizontal (GHI), and global tilted irradiance (GTI), plus sun azimuth and elevation; GTI respects a user-supplied tilt via solarTiltAngle. Values use the API’s standard units (e.g., W/m² for radiation), are hourly with sensible daily aggregations, and integrate seamlessly with other weather variables for bankable wind/solar assessments.
Extended wind
Elements: windspeed50, winddir50, windspeed80, winddir80, windspeed100, winddir100
Reference height: 50 m, 80 m, 100 m above ground
Units: mph, km/h, or m/s based on unitGroup
Aggregation: when requested as daily, hourly values are averaged for the day
Availability: forecast and historical hourly from 2015‑01‑01 onward
Example
&elements=datetime,temp,windspeed50,winddir50,windspeed80,winddir80,windspeed100,winddir100Extended solar radiation and sun angle
Elements: dniradiation, difradiation, ghiradiation, gtiradiation, sunelevation, sunazimuth
Units: W/m² for radiation; degrees for sun angles
Notes: ghiradiation = diffuse + direct × cos(sunelevation). gtiradiation uses the tilt angle you pass via solarTiltAngle.
Aggregation: For hourly data, values typically represent the average over the preceding hour; daily sunelevation is the max over the day
Availability: forecast and historical hourly from 2015‑01‑01 onward
Example
&elements=datetime,ghiradiation,dniradiation,difradiation,gtiradiation,sunazimuth,sunelevation&solarTiltAngle=45Radar‑derived precipitation and reflectivity (beta)
Radar-derived fields complement station-based precipitation by exposing precipremote (radar precipitation estimate) and reflectivity (dBZ). For sparse station coverage you can prefer radar amounts in the core precip field using options=radarthreshold, which substitutes radar precipitation when no physical weather station is within the chosen distance. Reflectivity provides intensity context (e.g., higher dBZ for heavier precipitation or hail), and minute-level requests enable high-resolution event analysis. Radar availability is currently region-dependent and may evolve as the feature exits beta.
Availability: beta; currently US and southern Canada; API structure may change
Elements: precipremote – radar‑derived precipitation estimate, reflectivity – radar reflectivity, reported in dBZ;
typical guide: <20 dBZ: light precipitation, 20–40 dBZ: moderate precipitation (rain or snow), >50 dBZ: heavy rain, hail, or severe storms
Examples
Request station and radar precipitation together (CSV)
&include=hours&elements=datetime,precip,precipremoteAdd reflectivity (JSON minutes)
&include=minutes&elements=datetime,precip,reflectivity,precipremotePrefer radar precipitation when stations are sparse
&include=minutes&elements=datetime,precip,reflectivity,precipremote&options=radarthreshold_25000Icons
The icon field holds a text value that users can use to indicate which icon to show when displaying the weather data. For more information, and sample icons sets, please see Defining the icon set parameter in the Weather API.
Descriptions and language support
The text descriptions that are included can be returned in different languages using the ‘lang’ API parameter.
For more information, please see the Timeline Weather API documentations and How to create or modify language files.
Dates and Times
These locate each record in time, with dates and times formatted in local ISO-8601. By default formatted dates and times will be in the timezone of the requested location. datetimeEpoch, the number of seconds since 1st January 1970, is always in UTC (GMT) time.
For more information on how dates and times are returned in the Weather API results, see Dates and Times in the Weather API.
Elements: datetime,datetimeEpoch,timezone,tzoffset .
Location & request metadata
If the requested data includes address, the address information is included in the return value. In addition, the latitude and longitude of the requested locations are returned using decimals degrees. The longitude value are zero based at the prime meridian. Values west of the prime meridian are negative and east are positive.
These describe the requested place and the processing cost. Internally Visual Crossing Weather uses latitude and longitude for locations. Address will match the requested locations, resolvedAddress may include a updated location to clarify which location was used. Name can be used to uniquely identify the location without relying on the address text (such as for a database join).
Elements: queryCost,latitude,longitude,resolvedAddress,address,elevation,name.
Contributing Weather Stations
For historical observations, indicates the weather stations that were used for creating the observation. This is a list of weather station names, their ID within the Visual Crossing weather data platform and the distance from the requested location to the weather station. For more information on how weather station data is combined, please read more.
General weather data structure
We aim to keep the data set structure as consistent as possible between the three main categories of data – weather forecast, historical weather observations and historical weather summaries. This allows you to easily switch between using data for weather forecast and historical records within the same data and can be useful in many applications. All the data sets include the following characteristics:
Data Set Structure
All data sets are a simple table structure which is available in multiple formats including plain text delimited such as CSV, JSON and ODATA. The data includes a single row of headers information indicating the information in the column. These column headers will either be in a human readable header that may be translated or in a single, short form which is not translated. The short form is typically used for Weather API usage to make it easier to consume the data. When using the Weather API, the shortColumnNames parameters indicates whether or not short column names will be used.
Hourly and Daily Dataset Aggregation
All data within the a system is calculated at the hourly data level for accuracy and consistency. When requests are made for longer time periods, such as daily weather forecast or monthly historical summaries, the hourly data is aggregated using average (mean), sum, minimum or maximum functions. The individual column documentation below explains the aggregation method used.
Unit group
The units of the data are specified by the overall unit group requests such as metric, US units etc. This unit group defines the unit of measure used for each column type – all columns of the same variable type will have the same unit. For example, Celsius will be used for all temperature related quantities when the unit group is set to metric.
Empty values
Empty values (or null values) are used within the data set to indicate an absence of data, such as missing weather information or unknown data. They are not used to indicate a zero value. For example, an unknown precipitation value will be marked as empty or null. A zero amount of precipitation will be indicated by the value zero.
Weather element availability
We aim to include all weather elements such as temperature, wind, precipitation etc. for all locations. Unfortunately not all locations report all weather elements. In those cases the columns will be included in the data but include null values. We continue to expand the availability of weather elements as we add additional data sets and data processing.
Questions or need help?
If you have a question or need help, please post on our actively monitored forum for the fastest replies. You can also contact our Support Team.