We have deprecated the v1 APIs of weather data and the v1 APIs of traffic messages. The replacing v2 APIs are already available.

Removal dates

• 3 November 2026: the v1 forecast APIs, i.e. /api/weather/v1/forecast-sections/forecasts, /api/weather/v1/forecast-sections-simple/forecasts and their /{id}/forecasts versions.
• 13 April 2027: the other v1 weather data APIs and all v1 traffic message APIs.
• 13 April 2027: the DATEX II 2.2.3 APIs. We announced earlier that they would be removed on 20 October 2026. The removal is moved to the same date as the v1 traffic message APIs.

The deprecated APIs are also listed on the API changes page. Please move to the replacing APIs well before the removal date.

What needs to change

For most APIs it is enough to change v1 to v2 in the path. The content stays the same. The APIs listed below change more.

Forecasts

/api/weather/v1/forecast-sections/forecasts and the other forecasts endpoints

• The forecasts come from a new source, so the values and observation times are not the same as in v1.
• weatherSymbol is now a number and uses a different set of codes. v1 used Vaisala symbols (e.g. d100), v2 uses the Finnish Meteorological Institute’s SmartSymbol codes (e.g. 7). 100 is added to the code at night. The symbols are available on the Finnish Meteorological Institute’s GitHub.
• forecastConditionReason is removed. The roadCondition it contained is now directly under the forecast. Its other fields (precipitationCondition, windCondition, freezingRainCondition, winterSlipperiness, visibilityCondition and frictionCondition) are removed without a replacement.
• reliability is removed.
• roadCondition can have the value NOT_KNOWN.
• overallRoadCondition: the value CONDITION_COULD_NOT_BE_RESOLVED is replaced by NOT_KNOWN.
• dataUpdatedTime is given at the response and forecast section level, but no longer in each forecast.

Sensor value history

/api/weather/v1/stations/{id}/data/history

• The list values is now called sensorValues.

Traffic messages

All JSON APIs:

• Values of enumerated fields are written differently. v1 returns for example ROAD_WORK and HIGH, v2 returns road work and high. This applies to fields such as situationType and severity.

/api/traffic-message/v1/messages

• The message type was selected with the situationType parameter. In v2 each type has its own API: roadworks, traffic-announcements, weight-restrictions and exempted-transports.
• inactiveHours is replaced by the parameters from and to. If from is not given, messages from one hour ago onwards are returned.

/api/traffic-message/v1/messages/{situationId}

• v1 returned all versions of the message by default. v2 returns only the latest version.
• All versions are available at /api/traffic-message/v2/messages/{situationId}/history. It returns a list of messages without the surrounding FeatureCollection structure.

/api/traffic-message/v1/messages.datex2 and /api/traffic-message/v1/messages/{situationId}.datex2

• These return DATEX II 2.2.3, and there is no v2 version in the same path. The replacing APIs use DATEX II 3.5 and 3.7, e.g. /api/traffic-message/v2/roadworks/datex2-3.7.xml and /api/traffic-message/v2/messages/{situationId}/datex2-3.7.xml.