Interactive Map to Degree-Day Calculator for Great Lakes Central USA
Introduction Suggestions for use
(NOTE: click your browser's RELOAD or REFRESH button for latest images)

Degree-Day Maps created daily using a 32° F. lower threshold:
Jan 1 - yesterday Finished Map (click for larger version)
Current Year

Interactive GIS interface to degree-day
calculator: select region, size and click GO

Region
Mapsize pixels       
GL US this year to date
new googlemaps interface
Normals (Historical avgs)

GL US Normals to date
Deviations from Normals

GL US deviations from normal to date

Degree-Day Maps created daily using a 41° F. lower threshold:
Jan 1 - yesterday Finished Map (click for larger version)
Current Year

Interactive GIS interface to degree-day
calculator: select region, size and click GO

GL US this year to date
new googlemaps interface
Normals (Historical avgs)

GL US Normals to date
Deviations from Normals

GL US deviations from normal to date

Degree-Day maps created daily using a 50° F. lower threshold:
Jan 1 - yesterday Finished Map (click for larger version)
Current Year

Interactive GIS interface to degree-day
calculator: select region, size and click GO

GL US this year to date
new googlemaps interface
Normals (Historical avgs)

GL US Normals to date
Deviations from Normals

GL US deviations from normal to date

Introduction
These maps are calculated daily using the GIS GRASS 5.4, and are based on 1) near-real time temperature data from numerous AgriMet, HydroMet, National Weather Service, RAWS, and Snotel weather stations, 2) historical average temperature data from numerous stations, 3) PRISM monthly max and min temperature maps, and 4) corrections based on inverse-distance squared inter polations of differences between PRISM map-based and real-time degree-day calculations.  See More info. on methodology for creating DD maps. Also try out our Degree-day Mapping Calculator for control over thresholds, calculation method, d ates, and mapping options.

Suggestions for Use
With these maps, you can 1) track the extent of degree-day (heat unit) build-up so far this growing season using 3 common thresholds: 32°, 41°, and 50° F, 2) compare this year's heat unit build-up with 30-year historical average or "normal" heat units, 3) monitor deviations between the current year and normal heat-unit build up (which indicates how much warmer or cooler than normal the year has been so far), 4) select the full region or a single state and use the interactive interface, 5) with GRASS Links, interact with these maps by zooming and querying degree-days at specific locations, and use the site-specific degree-day calculator for the nearest weather station to where you click in the map.


[IPM Weather/Degree-Days Home] [Intro] [US DD Mapmaker] [DD Models and Calculator] [Links]


Integrated Plant Protection Center at OSU Extension Service at Oregon State University National Plant Diagnostics Network Western
Region Pest Management Center
This page updated Dec 1, 2008
Contact Len Coop at coopl@science.oregonstate.edu if you have any questions about this information.