Growing Degree Day Resources

Using Degree Days for Improved Timing of Insect Pest Management

Pest management is an important aspect of agriculture, shade tree maintenance, and forest health. Correctly timing activities, such as pesticide applications or scouting for specific insect pests, can be challenging because of variation in the weather from one year to the next and from one part of the state to another. The growing degree day (GDD) resources below are available to help you improve your insect management activities in New Hampshire.

Learn More About Using Degree Days

• GDD for Pest Management
• GDD Informational Poster

Current Degree Day Accumulation

Get the current GDD for your area in 4 easy steps from NOWData:

1. In the left menu, under "Product selection", select "Accumulation graphs"
2. Under "Options", enter the start and end date, then select "GDD base 50" in the pulldown menu next to the word "Variable"
3. Click on "Station/Area selection" and enter your zipcode or city,state to bring up a list and map of nearby locations. Select the nearest location to your area of interest in the dropdown menu or from the map
4. Click "Go"

Average Seasonal Degree Day Accumulation Maps of New Hampshire

_50 GDD 100 GDD 150 GDD 200 GDD 250 GDD
300 GDD 350 GDD 400 GDD 450 GDD 500 GDD
550 GDD 600 GDD 650 GDD 700 GDD 750 GDD
800 GDD 850 GDD 900 GDD 950 GDD 1000 GDD
1050 GDD 1100 GDD 1150 GDD 1200 GDD 1250 GDD
1300 GDD 1350 GDD 1400 GDD 1450 GDD 1500 GDD
1550 GDD 1600 GDD 1650 GDD 1700 GDD 1750 GDD
1800 GDD 1850 GDD 1900 GDD 1950 GDD 2000 GDD
2050 GDD 2100 GDD 2150 GDD 2200 GDD 2250 GDD
2300 GDD 2350 GDD 2400 GDD 2450 GDD 2500 GDD

Degree Day Thresholds of Common Insect Pests

• Conifer pests
• Landscape pests
• Tree fruit pests

This project is the result of a cooperative effort between the New Hampshire Department of Agriculture, Markets & Food, the New Hampshire State Climate Office, and the US Forest Service, Northeastern Area State & Private Forestry, Forest Health Protection.