Historical Weather Data Fields
Historical Data Fields Reference
FreeThis page provides a complete reference of all historical weather data fields available through the Tomorrow.io Weather API, including their descriptions, units, data types, availability periods, and interface compatibility.
Historical data fields are available for queries spanning from January 1st, 2000 onwards, with a 7-day lag from the current date for data quality assurance.
📋 API Compatibility
These field names are used with APIs that support the fields parameter:
- ✅ Historical Weather API (
/v4/historical) - POST method - ✅ Climate Normals API (
/v4/historical/normals) - POST method - ❌ Recent History API (
/v4/weather/history/recent) - GET method, returns all fields automatically
Historical Data Fields Overview
The historical weather data fields provide access to past weather conditions with comprehensive coverage across multiple meteorological parameters. Use these field names in your historical API requests using the fields parameter.
Key Features:
- Extensive Coverage: Data available from January 1st, 2000 onwards for most fields
- Multiple Interfaces: Compatible with Timeline (T), Insights (I), Map (M), and Route (R) interfaces
- Flexible Aggregation: Daily, hourly, and custom time interval support with statistical aggregations
- Global Availability: Worldwide land coverage with consistent data quality
- 7-Day Lag: Recent data up to 7 days ago to ensure accuracy and completeness
Field Information Guide
Understanding the Reference Table:
- Data Field: The exact field name to use in the
fieldsarray for Historical Weather API and Climate Normals API - Description: Technical description of what the field measures
- Values/Units: Range and units for metric/imperial systems
- Data Type: Expected data type (Number, Integer, String)
- Example: Sample value from actual historical data
- Related Fields: Other fields commonly used together
- Common Use Cases: Real-world applications and industries
- Query Parameter: How to request this field in API calls that support
fieldsparameter - Availability: Time range when historical data is available
- Interfaces: T=Timeline, I=Insights, M=Map, R=Route compatibility
Note: These field names apply to APIs that use the fields parameter. The Recent History API returns all fields automatically without field selection.
Historical Data Fields Reference
The table below contains all available historical weather data fields with detailed availability and interface information. Use these field names in the fields parameter for Historical Weather API and Climate Normals API requests.
| Data Field | Description | Values/Units | Data Type | Example | Related Fields | Common Use Cases | Query Parameter | Availability | Interfaces |
|---|---|---|---|---|---|---|---|---|---|
| Temperature Metrics | |||||||||
temperature | Air temperature measured at 2 meters above ground level | Metric: Celsius [-90,60] Imperial: Fahrenheit [-130,140] | Number | 18.5 | temperatureApparent, temperatureMin, temperatureMax, dewPoint | Climate analysis, agricultural planning, energy demand forecasting, historical trend analysis | fields=temperature | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
temperatureApparent | Perceived temperature accounting for humidity and wind effects ("feels like") | Metric: Celsius [-90,60] Imperial: Fahrenheit [-130,140] | Number | 16.2 | temperature, humidity, windSpeed | Human comfort studies, historical heat stress analysis, outdoor work safety assessments | fields=temperatureApparent | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
temperatureMin | Minimum temperature over the specified time interval | Metric: Celsius [-90,60] Imperial: Fahrenheit [-130,140] | Number | 12.1 | temperature, temperatureMax | Frost risk analysis, crop protection planning, cold weather historical patterns | fields=temperatureMin (daily timesteps only) | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
temperatureMax | Maximum temperature over the specified time interval | Metric: Celsius [-90,60] Imperial: Fahrenheit [-130,140] | Number | 24.8 | temperature, temperatureMin | Heat wave analysis, energy consumption modeling, historical extreme weather studies | fields=temperatureMax (daily timesteps only) | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
| Precipitation Metrics | |||||||||
precipitationIntensity | The rate of liquid equivalent precipitation at ground level | Metric: mm/hr [0,100] Imperial: in/hr [0,4] | Number | 2.3 | precipitationType, precipitationAccumulation | Flood risk modeling, historical storm analysis, infrastructure planning, agricultural irrigation | fields=precipitationIntensity | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
precipitationAccumulation | Total accumulated precipitation over the time interval | Metric: mm [0,500] Imperial: in [0,20] | Number | 15.7 | precipitationIntensity, precipitationType | Water resource management, drought analysis, reservoir planning, agricultural yield modeling | fields=precipitationAccumulation | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
precipitationType | Type of precipitation occurring at ground level | 0: None 1: Rain 2: Snow 3: Freezing Rain 4: Ice Pellets | Integer | 1 | precipitationIntensity, precipitationAccumulation | Winter weather analysis, road condition studies, aviation safety research, climate classification | fields=precipitationType | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
| Wind Metrics | |||||||||
windSpeed | Wind speed measured at 10 meters above ground level | Metric: m/s [0,100] Imperial: mph [0,224] | Number | 7.2 | windDirection, windGust, temperatureApparent | Wind energy assessments, historical storm tracking, fire spread modeling, transportation planning | fields=windSpeed | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
windDirection | Direction from which wind originates, measured clockwise from north | degrees [0,360] | Number | 245 | windSpeed, windGust | Pollution dispersal studies, wildfire behavior analysis, wind farm site assessment | fields=windDirection | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
windGust | Maximum brief increase in wind speed, usually less than 20 seconds | Metric: m/s [0,100] Imperial: mph [0,224] | Number | 15.8 | windSpeed, windDirection | Structural engineering analysis, historical storm damage assessment, aviation safety studies | fields=windGust | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
| Atmospheric Metrics | |||||||||
humidity | Relative humidity as percentage of moisture in air at 2m above ground | % [0,100] | Number | 73 | dewPoint, temperatureApparent | Agricultural disease modeling, building material studies, human comfort analysis | fields=humidity | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
pressureSeaLevel | Atmospheric pressure adjusted to mean sea level | Metric: hPa [800,1200] Imperial: inHg [23.6,35.4] | Number | 1013.2 | pressureSurfaceLevel | Weather system analysis, storm tracking, barometric pressure trends, aviation planning | fields=pressureSeaLevel | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
dewPoint | Temperature to which air must be cooled to become saturated with water vapor | Metric: Celsius [0,100] Imperial: Fahrenheit [32,212] | Number | 14.3 | temperature, humidity | Fog prediction models, frost risk assessment, HVAC efficiency studies, comfort indices | fields=dewPoint | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
| Cloud Cover & Visibility Metrics | |||||||||
cloudCover | Fraction of sky obscured by clouds when observed from a particular location | % [0,100] | Number | 45 | visibility, weatherCode | Solar energy modeling, satellite imagery analysis, aviation weather studies, photography planning | fields=cloudCover | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
visibility | Distance at which an object or light can be clearly discerned | Metric: km [0,50] Imperial: mi [0,31] | Number | 12.4 | cloudCover, precipitationIntensity | Transportation safety analysis, airport operations research, fog frequency studies | fields=visibility | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
| Solar Radiation Metrics | |||||||||
solarGHI | Global Horizontal Irradiance - total solar radiation received on horizontal surface | W/m² [0,1500] | Number | 425.7 | solarDNI, solarDHI, cloudCover | Solar panel efficiency analysis, renewable energy planning, agricultural growth modeling | fields=solarGHI | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
solarDNI | Direct Normal Irradiance - solar radiation received directly from sun | W/m² [0,1200] | Number | 687.3 | solarGHI, solarDHI, cloudCover | Concentrated solar power planning, tracking solar system analysis, solar resource assessment | fields=solarDNI | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
| Snow & Ice Metrics | |||||||||
snowAccumulation | Accumulated amount of new snowfall over the time interval | Metric: mm [0,1000] Imperial: in [0,40] | Number | 0 | precipitationType, precipitationIntensity | Winter operations planning, structural load analysis, ski resort management, road maintenance | fields=snowAccumulation | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
snowDepth | Total depth of snow on ground surface | Metric: mm [0,5000] Imperial: in [0,200] | Number | 0 | snowAccumulation, precipitationType | Avalanche risk assessment, water resource planning, winter sports industry, infrastructure design | fields=snowDepth | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
| Weather Code Metrics | |||||||||
weatherCode | Numerical code representing the most prominent weather condition | 1000: Clear 1001: Cloudy 1100: Mostly Clear 1101: Partly Cloudy 1102: Mostly Cloudy 2000: Fog 4000: Drizzle 4001: Rain 4200: Light Rain 4201: Heavy Rain 5000: Snow 5001: Flurries 5100: Light Snow 5101: Heavy Snow 6000: Freezing Drizzle 6001: Freezing Rain 7000: Ice Pellets 7101: Heavy Ice Pellets 8000: Thunderstorm | Integer | 1100 | precipitationType, cloudCover, precipitationIntensity | Historical weather pattern analysis, climate classification, extreme weather frequency studies | fields=weatherCode | Jan 1, 2000 - 7 days ago | Timeline (T), Insights (I), Map (M), Route (R) |
Usage Examples
Here are practical examples of how to use historical data fields with APIs that support the fields parameter:
Historical Weather API - Temperature Analysis
POST request with selected temperature fields:
Historical Weather API RequestBASH
POST https://api.tomorrow.io/v4/historical?apikey=YOUR_API_KEY
Content-Type: application/json
{
"location": [40.7128, -74.0060],
"fields": ["temperature", "temperatureMin", "temperatureMax", "humidity"],
"timesteps": ["1d"],
"startTime": "2024-01-01T00:00:00Z",
"endTime": "2024-01-31T23:59:59Z",
"units": "metric"
}Climate Normals API - Long-term Averages
POST request for climate normal fields:
Climate Normals API RequestBASH
POST https://api.tomorrow.io/v4/historical/normals?apikey=YOUR_API_KEY
Content-Type: application/json
{
"location": [40.7128, -74.0060],
"fields": ["temperatureAvg", "precipitationAccumulationSum", "humidityAvg"],
"timesteps": ["1d"],
"startDate": "01-01",
"endDate": "12-31",
"units": "metric"
}Recent History API - No Fields Parameter
GET request returns all fields automatically:
Recent History API RequestBASH
GET https://api.tomorrow.io/v4/weather/history/recent?location=40.7128,-74.0060×teps=1h&apikey=YOUR_API_KEY
Note: This API returns ALL available fields automatically.
No "fields" parameter is used or needed.⚠️ Important: The Recent History API does not use the fields parameter and returns all available weather data automatically.
Data Quality & Coverage
Temporal Coverage
- Start Date: January 1st, 2000
- End Date: 7 days ago (rolling)
- Resolution: Hourly and daily timesteps
- Lag Time: 7 days for quality assurance
Geographic Coverage
- Global Coverage: Worldwide land areas
- Resolution: High-resolution grid
- Data Sources: Multiple meteorological sources
- Quality Control: Automated validation processes