Data Annoucement:  01 October 2025

PRISM Data Format and Website Changes

Multiple PRISM data format, structure, and availability changes went into effect on 01 October 2025. Additionally, changes to web services went into effect, and changes to the website went live.

Summary of Data Format, Structure, and Availability Changes

  • All PRISM time series datasets (4km and 800m) transitioned from BIL to Cloud Optimized GeoTiff (COG) format. See our Data Formats page.
  • Filenames now use the more consistent internal PRISM naming convention and no longer contain data stability status (early, provisional, stable). See our Data Formats page for more information.
  • Directory structures in our FTP repository and browseable data directory now contain levels for region (us, hi, ak, pr) and an additional resolution (400m). Time series data for Hawaii (400m), Alaska (4km and 800m), and Puerto Rico (400m) are in development by the PRISM Group and will be made available as they are completed.
    • Filenames now include the following spatial resolution indicators: 15s, 30s, or 25m
    • 15s ≡ 400m, 30s ≡ 800m, 25m ≡ 4km (s = seconds, m = minutes)
  • Web service calls have changed to a single, consolidated resource that provides all PRISM data. Please review our web services documentation in order to begin using web services or to modify your existing requests.
Summary of Website Changes

  • Website navigation is now enabled by a dynamic navigation bar that allows for better organization of, and access to, website content.
  • PRISM time series data access has been collapsed into a single page where any PRISM time series grid can be downloaded.
  • Dynamic data stability information has been added to the time series data and normals web pages.
  • Composite .zip packages (e.g., all days in a year) have been eliminated. Please use our bulk data download services such as web services and FTP for fetching data in bulk.
  • A map graphics archive has been implemented that includes a map graphic for every PRISM time series grid, plus month-to-date and anomaly products (over 600K map graphics in total). Map graphics are automatically re-created whenever PRISM grids are updated.
  • New map graphics such as month-to-date anomalies are available on the Anomalies page and in the map graphics archive.
  • Behind the scenes, the website codebase has been prepared for the upcoming Hawaii, Alaska, and Puerto Rico time series data.