In addition to the daily and hourly resolution data that the Timeline Weather API supports, the API now also supports sub-hourly, or minute-level data. While the hourly and daily data is sourced from official weather stations, sub-hourly data may be sourced from both official and additional stations to provide greater data granularity.
Beta Availability
Sub-hourly data features in the Timeline Weather API are currently in testing and are available to Corporate and Enterprise plans for feedback. During this testing phase, the parameters, response format, and response structure may change. For more information or to participate in the testing, please contact support.
Retrieving Sub-Hourly Data in a Timeline Weather API Request
To retrieve sub-hourly data, an additional include property—minutes—must be added to the request.
For JSON requests, minutes can be included alongside other data grids such as days and hours. The minute-level data will appear as a child of each hour in the response
For CSV requests, the minutes data grid must be included as the only data grid property.
Example: Requesting Sub-Hourly Data in CSV Format
The following API request retrieves CSV-formatted sub-hourly data for London, UK, using the yesterday dynamic date:
https://weather.visualcrossing.com/VisualCrossingWebServices/rest/services/timeline/London,UK/yesterday?unitGroup=us&key=YOUR_API_KEY&contentType=csv&include=minutesSample Output (CSV)
By default, the data is returned in 15-minute intervals:
name,datetime,temp,feelslike,dew,humidity,,..
"London, England, United Kingdom",2025-01-28T00:00:00,47.2,40.7,39.5,74.52,...
"London, England, United Kingdom",2025-01-28T00:15:00,47.1,40.7,39.5,74.73,...
"London, England, United Kingdom",2025-01-28T00:30:00,47.1,40.7,39.5,74.73,...
"London, England, United Kingdom",2025-01-28T00:45:00,47.1,40.7,39.8,75.6,...
(additional elements removed for clarity)
Modifying the Time Interval
The default sub-hourly interval is 15 minutes. You can modify this using the minuteinterval option.
For example, to request 30-minute intervals, include the minuteinterval_30 option:
https://weather.visualcrossing.com/VisualCrossingWebServices/rest/services/timeline/London,UK/yesterday?unitGroup=us&key=YOUR_API_KEY&contentType=csv&include=minutes&options=minuteinterval_30Available Time Intervals:
Historical Data: Smallest available time interval is 5-10 minutes, depending on data availability.
Forecast Data: Minimum available time interval is 15 minutes.
If a requested historical interval is shorter than the available station data, the API interpolates the values to smoothly fit the available data. However, forecast data is not interpolated below 15-minute intervals.
Example: Requesting Sub-Hourly Data in JSON Format
The following API request retrieves JSON-formatted sub-hourly data:
https://weather.visualcrossing.com/VisualCrossingWebServices/rest/services/timeline/London,UK/yesterday?unitGroup=us&key=YOUR_API_KEY&contentType=json&include=minutesSample Output (JSON)
The response follows the standard Timeline Weather API JSON format, with minute-level data nested under each hourly node:
"hours": [
{
"datetime": "00:00:00",
"temp": 45.9,
"minutes": [
{
"datetime": "00:00:00",
"temp": 45.9
},
{
"datetime": "00:15:00",
"temp": 45.6
},
{
"datetime": "00:30:00",
"temp": 45.6
},
{
"datetime": "00:45:00",
"temp": 46.3
}
]
}
]
Minute-level data is retrieved separately and does not aggregate in the same way that hourly data aggregates into daily data. This is because different weather stations are used for each request, leading to some differences between hourly and sub-hourly values.
Query Cost for Sub-Hourly Data
Each row of sub-hourly data counts as one record cost for both historical and forecast data.
For example, a single day of 15-minute interval data includes:
- 24 hours × 4 intervals per hour = 96 query costs
JSON-formatted results will include the total query cost in the response.
Upgrading from the legacy sub hourly weather API
The new Timeline Weather API offers several advantages over the legacy sub-hourly API:
More granular intervals (5-10 minutes for historical data, 15 minutes for forecast data) Consistent format with the Timeline Weather API (JSON/CSV response structure) Enhanced station sources for better accuracy
For users transitioning from the legacy sub-hourly API, the main changes include:
- Using the
include=minutesparameter instead of separate endpoints - Adjusting queries to align with the new query cost model
- Handling data in the nested hourly → minute-level JSON structure
For assistance with migration, please contact our support team.
Start Using Sub-Hourly Weather Data Today!
The addition of sub-hourly data in the Timeline Weather API provides more precise weather insights than ever before. If you’re a Corporate or Enterprise plan user, try it out today and share your feedback!
Questions? Contact our support team.