Issue 5, June 17, 2021
Modified Growing Degree Days (Base 50⁰ F, March 1 through June 13)
| Station Location | Actual Total | Historical Average (11 year) | One- Week Projection |
| Freeport | 852 | 691 | 980 |
| St. Charles | 858 | 667 | 981 |
| DeKalb | 849 | 689 | 974 |
| Monmouth | 921 | 834 | 1064 |
| Peoria | 952 | 873 | 1093 |
| Champaign | 988 | 921 | 1125 |
| Springfield | 1024 | 1036 | 1176 |
| Perry | 1006 | 970 | 1159 |
| Brownstown | 1074 | 954 | 1230 |
| Belleville | 1083 | 1117 | 1245 |
| Rend Lake | 1163 | 1202 | 1318 |
| Carbondale | 1129 | 1141 | 1287 |
| Dixon Springs | 1150 | 1173 | 1307 |
Insect development is temperature dependent. We can use degree days to help predict insect emergence and activity. Home, Yard, and Garden readers can use the links below with the degree day accumulations above to determine what insect pests could be active in their area.
GDD of Landscape Pests
GDD of Conifer Pests
Degree day accumulations calculated using the Pest Degree-Day Calculator Calculator (a project by the Department of Crop Sciences at the University of Illinois and the Illinois Water Survey).
Degrees days are accumulating rapidly with these very warm days. Japanese beetle emergence generally occurs when 1020-2130 DD have accumulated. We may start seeing Japanese beetles soon in parts of Illinois!
Author:
Kelly Estes