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National Weather Service
Hourly Precipitation Analysis
Local weather forecast by "City, St" or zip code
Downloading Hourly Gridded Rainfall Data

Last Update: 4/22/2011 1947 GMT

(1) Select Download(2) Select Date
Month      Day      Hour      Year      
(3) Press the "Download" Button

File NameFiles IncludedSize
0.5 to 7.0 MB

General Information

The precipitation data are quality-controlled, multi-sensor (radar and rain gauge) precipitation estimates obtained from National Weather Service (NWS) River Forecast Centers (RFCs). The original data are in XMRG format and projected in the Hydrologic Rainfall Analysis Project (HRAP) grid coordinate system, a polar stereographic projection true at 60°N / 105°W. Our software reads each participating RFC's XMRG file and grabs the hourly precipitation estimate for each HRAP grid cell.

Use the form above to download these files. Alternatively, you can download a progam called wget that mimics ftp capability. Due to increased web security, the anonymous FTP server is no longer available.

At this time, data files prior to 2008 are unavailable from this page.

If you have any questions or problems, please contact

Shapefile Information

The shapefile contains the following fields:

  1. id - a unique value for each grid bin
  2. hrapx - column number of the HRAP grid cell (higher numbers are further north)
  3. hrapy - row number of the HRAP grid cell (higher numbers are further east)
  4. latitude of the HRAP grid point
  5. longitude of the HRAP grid point
  6. globvalue - 24-hour precipitation value in inches. "-1" values correspond to "No Data", e.g. data over the ocean. "-2" values correspond to "Missing Data", e.g. an incomplete dataset.

The second download option "Legend File" will help you reproduce the color scheme we are using. If using ArcView, you will need to copy it into your c:\esri\av_gis30\arcview\legend_avl\ directory and load it manually through the legend editor. This file does not change from day to day.