Road Weather Data API

Gain the accurate, actionable road weather data you need for enhanced safety, maintenance operations, and efficiency.

    Driving condition forecasts

    This API provides surface state, visibility, and other weather data that affect driving and maintenance operations. More than 40 driving condition codes are divided into three severity classes, giving users a unified, comprehensive methodology for assessing road conditions in real-time. Vehicle sensor data can be integrated for even finer-resolution weather awareness, and the API accounts for potential effects of road maintenance actions such as plowing and salting.

    Vaisala's experts have led the field in road weather forecasting for many years. Our forecasts are trusted in the winter maintenance industry by road authorities in a number of countries.

    Severity & conditions

    The API presents 40+ variations of codes to express driving conditions. These are broken into three severity levels: normal, risky, and hazardous conditions. Examples include:

    Normal Conditions

    • Dry road
    • Moist road
    • Wet road
    • Light/moderate rain (some slush/snow when winter tires assumed)

    Risky Conditions

    • Heavy rain
    • Strong winds
    • Patches of fog
    • Risk of aquaplaning

    Hazardous Conditions

    • Very strong winds
    • Risk of damaging hail
    • Poor visibility due to: very heavy rain, dense fog, blowing snow, blizzard
    • Slippery due to: snow, icy road, water on icy road, slush on road, freezing rain

    Flexible delivery

    Users may elect to receive data in coordinate-based, gridded, or road-segment options.


    Driving condition information for the current coordinates of a vehicle, or on a route that consists of several coordinates and projected timestamps, can be queried in XML or JSON formats.

    Gridded data: 

    Customers that would like to map the road condition information into road segments themselves, can have the forecast data delivered as longitude-latitude grids.

    Road segments: 

    Driving conditions data can be delivered in batches of pre-set locations that are updated regularly, usually once per hour, removing the need to map the data into road segments.

    Vaisala team collaborating in office

    Enhance your Road Operations, Management, and Safety

    Contact Vaisala today to learn more about integrating the Road Weather Data API and delivering on your commitments to your road-faring community.

    Contact us