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 | 23 | 136 | 442 | 709 | 899 | 859 | 597 | 276 | 52 | 3 | 4001 |
| GDD Base 45 |
0 | 0 | 8 | 61 | 296 | 559 | 744 | 705 | 449 | 156 | 19 | 1 | 3000 |
| GDD Base 50 |
0 | 0 | 1 | 22 | 172 | 410 | 589 | 550 | 306 | 70 | 6 | 0 | 2130 |
| GDD Base 55 |
0 | 0 | 0 | 6 | 85 | 268 | 434 | 396 | 181 | 24 | 1 | 0 | 1398 |
| GDD Base 60 |
0 | 0 | 0 | 1 | 35 | 148 | 282 | 247 | 87 | 5 | 0 | 0 | 807 |
| MGDD* Base 50 |
0 | 0 | 12 | 76 | 251 | 431 | 586 | 554 | 345 | 129 | 17 | 1 | 2406 |
| Date of Last Spring Occurrence | Date of First Fall Occurrence | |||||||||
| Base Temp °F |
Median | Early | 90% | 10% | Late | Median | Early | 90% | 10% | Late |
| 32 | 5/10 | 4/21 | 4/27 | 5/25 | 6/04 | 10/08 | 9/23 | 9/24 | 11/02 | 11/13 |
| 30 | 5/03 | 4/17 | 4/23 | 5/17 | 5/22 | 10/14 | 9/23 | 9/25 | 11/12 | 11/16 |
| 28 | 4/24 | 4/06 | 4/09 | 5/09 | 5/13 | 10/24 | 9/24 | 9/30 | 11/12 | 11/19 |
| 24 | 4/12 | 3/23 | 3/27 | 4/21 | 4/26 | 11/09 | 10/09 | 10/17 | 11/17 | 11/23 |
| 20 | 4/02 | 3/12 | 3/18 | 4/10 | 4/13 | 11/20 | 10/24 | 11/03 | 12/03 | 12/22 |
| 16 | 3/27 | 3/06 | 3/15 | 4/09 | 4/11 | 11/25 | 11/03 | 11/12 | 12/19 | 12/22 |
| Base Temp °F |
Median | Shortest | 10% | 90% | Longest |
| 32 | 150 | 128 | 136 | 163 | 199 |
| 30 | 166 | 135 | 138 | 199 | 205 |
| 28 | 178 | 135 | 158 | 210 | 221 |
| 24 | 211 | 176 | 190 | 228 | 238 |
| 20 | 230 | 207 | 215 | 259 | 274 |
| 16 | 245 | 218 | 221 | 267 | 285 |