Roadside Weather Information System


The Department has 150 weather, visibility, and environmental sensing units located on the highway system, mostly in rural areas or areas with recurrent weather conditions. Locations typically include mountain passes/key elevations, Central Valley fog areas; and desert high wind areas. Districts 2, 3, 6, 8 and 10 have nearly all of the RWIS locations. Districts 2 and 3 share dynamic RWIS information via the Internet, and an effort is underway to standardize and centralize the information databases by Fall 2005. Portable RWIS units are typically placed at a location seasonally, such as during the October-March fog season in the Central Valley, or near multi-month construction zones.

File formats include CSV, JSON, TXT and XML. Each file format contains the same data set. These files are available for integration into your application and are available via the HTTP protocol. There is no charge for the use of this data.

Conditions of Use

Please read the Conditions Of Use before using these data sets.

Data Format and File Layout

Data is available in four file formats that contain the same information to allow easy integration into your application. Included below are the file format layouts:

Data Description

Data in each of these file formats are defined in the following documents:

Deprecated Files

The files listed in the link below are deprecated and should not be used for new software development. Support and documentation for these feeds is limited.

File Locations

Data sets are broken up by Caltrans Districts. A map of the Caltrans Districts can be found here.

Page Modified On: 05/12/16 12:39:57 PM