US Degree-Day Mapping Calculator vII (New R based)
New US Degree-Day Mapmaker

Input Options:   Thresholds: ° F.  lower:  upper:   calc. type:
  Start:  End:   Year:
Mapping Options:  Region:     Downscale to High Resolution:  
Temperature Scale in:  

 Instructions - how to make a degree-day map

 New Version - now with forecasts through end of current year.
 Uses daily PRISM 4km resolution maps. Data processing uses the "R" language.

   1. Select all options starting with thresholds, calculation type, start date (generally Jan 1st is used).
      For End Date, NEW any date through Dec 31st can be used (will use a forecast for future dates).
      Otherwise you may want to use the default date (yesterday)
        future dates use extended (up to 7-month) forecasts and then 10-year averages.
      Region: the larger the region the longer the processing time.
   3. Downscaling greatly increases processing time; not recommended for full US.
   4. Limiting conditions include:
        a) Input thresholds in degrees F. only.
        b) Both F. and C. are options for map results.
        c) Lower threshold must be AT or ABOVE 32F only.
        d) No years before 1981, no future years are supported at this time.
   5. After mapmaking has finished, click on the provided link to your output maps directory.
       View PNG or GeoTiff files and right-button click to download to your GIS program.

[Home] [Intro] [Data Access Maps] [DD Calc & Models] [Links]
APHIS PPQ Integrated Plant Protection Center at OSU Oregon State University The PRISM Group at OSU Western
 Region Pest Management Center National Institute
 for Food and Agriculture

This project funded in part by grants by USDA-APHIS-PPQ-CPHST, several USDA-NIFA programs,
and by the statewide Integrated Pest Management Program of IPPC at Oregon State University.

This program on-line since Nov. 8, 2017 Last updated Jan. 2, 2020 version II.02
Contact Len Coop at if you have any questions about this information.