Growing Degree Days (GDDs)
GDDs are becoming a more popular way to determine when to control insect pests that attack ornamental trees and shrubs.
- Growing Degree Days Statistics - National
- National Weather Service (NOAA), Climate Prediction Center
- ATTRA Phenology Information
- National Sustainable Agriculture Information Service - Publication #IP157
- Growing Degree Days FAQ's
- Weather Underground
- Growing Degree Days for New Hampshire
- University of New Hampshire Cooperative Extension
- New York Growing Degree Day Tracker
- Cornell University - Woody Ornamentals Entomology
- Pennsylvania State Climatologist
- provide accurate and complete climatological data for the commonwealth of PA
