Growing Degree Day Averages
Derived from 1971-2000 Data
| Element | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN |
| GDD Base 40 |
0 | 0 | 25 | 196 | 557 | 793 | 962 | 886 | 571 | 248 | 29 | 1 | 4197 |
| GDD Base 45 |
0 | 0 | 8 | 110 | 408 | 643 | 807 | 731 | 424 | 141 | 11 | 0 | 3228 |
| GDD Base 50 |
0 | 0 | 2 | 55 | 271 | 494 | 652 | 576 | 285 | 66 | 3 | 0 | 2366 |
| GDD Base 55 |
0 | 0 | 0 | 24 | 158 | 348 | 497 | 422 | 168 | 23 | 0 | 0 | 1615 |
| GDD Base 60 |
0 | 0 | 0 | 9 | 79 | 213 | 344 | 272 | 83 | 6 | 0 | 0 | 991 |
| MGDD* Base 50 |
0 | 0 | 18 | 134 | 343 | 504 | 638 | 576 | 339 | 143 | 16 | 0 | 2667 |
| Date of Last Spring Occurrence | Date of First Fall Occurrence | |||||||||
| Base Temp °F |
Median | Early | 90% | 10% | Late | Median | Early | 90% | 10% | Late |
| 32 | 5/04 | 4/17 | 4/24 | 5/18 | 5/24 | 10/02 | 9/12 | 9/20 | 10/13 | 10/22 |
| 30 | 4/28 | 4/04 | 4/12 | 5/09 | 5/16 | 10/07 | 9/22 | 9/24 | 10/20 | 11/03 |
| 28 | 4/24 | 3/29 | 4/09 | 5/02 | 5/10 | 10/15 | 9/23 | 10/02 | 11/02 | 11/09 |
| 24 | 4/13 | 3/24 | 4/03 | 4/25 | 5/06 | 10/30 | 9/24 | 10/05 | 11/14 | 11/16 |
| 20 | 4/09 | 3/18 | 3/24 | 4/17 | 5/06 | 11/05 | 10/03 | 10/19 | 11/16 | 11/27 |
| 16 | 4/04 | 3/08 | 3/16 | 4/11 | 4/17 | 11/12 | 10/19 | 10/29 | 11/26 | 12/05 |
| Base Temp °F |
Median | Shortest | 10% | 90% | Longest |
| 32 | 151 | 124 | 129 | 164 | 176 |
| 30 | 161 | 138 | 142 | 183 | 207 |
| 28 | 176 | 139 | 159 | 202 | 210 |
| 24 | 199 | 141 | 173 | 218 | 233 |
| 20 | 213 | 150 | 191 | 234 | 251 |
| 16 | 221 | 193 | 210 | 246 | 267 |