Below are links to maps that indicate the average calendar dates when regions surrounding the Great Lakes reach a particular accumulation of degree days (base 50 degrees F) with measurement beginning March 1. Read more about using degree days for pest management.

Note: The maps on this web site use Adobe pdf reader. A free version is available at: http://www.adobe.com/products/acrobat/readstep2.html

Tip: If you would like to save a copy of the maps to your computer for easier viewing, please follow these steps:
1. Open the document in your browser.
2. Go to File, Save As, choose where to save the document on your computer, and hit "Save."

The file is then available to view while you are not connected to the Internet.

For more weather-based pest management information, visit the station closest to your location at:
Enviro-weather: Weather data from the Michigan Agriculture Weather Network.