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 | 16 | 129 | 448 | 665 | 813 | 751 | 463 | 183 | 22 | 0 | 3442 |
| GDD Base 45 |
0 | 0 | 4 | 69 | 310 | 516 | 659 | 597 | 321 | 96 | 7 | 0 | 2541 |
| GDD Base 50 |
0 | 0 | 0 | 33 | 194 | 371 | 504 | 442 | 198 | 41 | 2 | 0 | 1762 |
| GDD Base 55 |
0 | 0 | 0 | 14 | 108 | 237 | 352 | 292 | 105 | 14 | 0 | 0 | 1109 |
| GDD Base 60 |
0 | 0 | 0 | 5 | 51 | 125 | 211 | 160 | 47 | 3 | 0 | 0 | 597 |
| MGDD* Base 50 |
0 | 0 | 13 | 99 | 291 | 410 | 518 | 466 | 268 | 110 | 12 | 0 | 2156 |
| Date of Last Spring Occurrence | Date of First Fall Occurrence | |||||||||
| Base Temp °F |
Median | Early | 90% | 10% | Late | Median | Early | 90% | 10% | Late |
| 32 | 5/26 | 5/01 | 5/13 | 6/10 | 6/22 | 9/23 | 8/14 | 9/05 | 10/06 | 10/16 |
| 30 | 5/18 | 4/28 | 5/03 | 6/05 | 6/22 | 9/26 | 9/07 | 9/19 | 10/11 | 11/03 |
| 28 | 5/10 | 4/17 | 4/24 | 6/02 | 6/22 | 10/02 | 9/07 | 9/21 | 10/18 | 11/06 |
| 24 | 4/29 | 4/06 | 4/09 | 5/11 | 5/19 | 10/20 | 9/20 | 9/25 | 11/08 | 11/26 |
| 20 | 4/20 | 4/01 | 4/06 | 5/02 | 5/05 | 11/02 | 10/02 | 10/13 | 11/14 | 2/01 |
| 16 | 4/08 | 3/18 | 3/23 | 4/18 | 4/26 | 11/09 | 10/13 | 10/20 | 11/20 | 2/01 |
| Base Temp °F |
Median | Shortest | 10% | 90% | Longest |
| 32 | 119 | 53 | 94 | 136 | 168 |
| 30 | 134 | 90 | 107 | 154 | 172 |
| 28 | 149 | 90 | 113 | 163 | 176 |
| 24 | 170 | 137 | 144 | 205 | 217 |
| 20 | 194 | 152 | 171 | 217 | 275 |
| 16 | 215 | 170 | 191 | 234 | 295 |