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 | 2 | 26 | 137 | 466 | 697 | 893 | 822 | 484 | 208 | 25 | 1 | 3724 |
| GDD Base 45 |
0 | 0 | 10 | 76 | 329 | 551 | 742 | 670 | 345 | 113 | 10 | 0 | 2820 |
| GDD Base 50 |
0 | 0 | 3 | 37 | 213 | 409 | 591 | 518 | 220 | 51 | 3 | 0 | 2029 |
| GDD Base 55 |
0 | 0 | 0 | 15 | 122 | 277 | 442 | 369 | 122 | 19 | 0 | 0 | 1358 |
| GDD Base 60 |
0 | 0 | 0 | 5 | 62 | 166 | 297 | 233 | 60 | 5 | 0 | 0 | 824 |
| MGDD* Base 50 |
0 | 1 | 15 | 96 | 313 | 451 | 593 | 537 | 302 | 135 | 15 | 1 | 2432 |
| Date of Last Spring Occurrence | Date of First Fall Occurrence | |||||||||
| Base Temp °F |
Median | Early | 90% | 10% | Late | Median | Early | 90% | 10% | Late |
| 32 | 6/06 | 5/06 | 5/13 | 6/26 | 7/12 | 9/14 | 8/06 | 8/24 | 10/06 | 10/12 |
| 30 | 5/28 | 4/30 | 5/07 | 6/17 | 7/12 | 9/21 | 8/15 | 9/04 | 10/06 | 10/12 |
| 28 | 5/27 | 4/22 | 4/29 | 6/15 | 6/17 | 9/26 | 8/15 | 9/07 | 10/12 | 11/01 |
| 24 | 5/13 | 4/08 | 4/15 | 5/30 | 6/02 | 10/02 | 9/06 | 9/19 | 10/17 | 11/06 |
| 20 | 4/21 | 3/26 | 4/05 | 5/18 | 5/26 | 10/13 | 9/24 | 9/27 | 11/06 | 11/10 |
| 16 | 4/08 | 3/14 | 3/20 | 5/03 | 5/17 | 11/01 | 9/24 | 10/15 | 11/13 | 11/16 |
| Base Temp °F |
Median | Shortest | 10% | 90% | Longest |
| 32 | 108 | 36 | 76 | 126 | 153 |
| 30 | 114 | 76 | 85 | 144 | 153 |
| 28 | 132 | 82 | 92 | 149 | 173 |
| 24 | 142 | 109 | 115 | 177 | 205 |
| 20 | 174 | 137 | 141 | 212 | 216 |
| 16 | 207 | 165 | 167 | 231 | 240 |