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 |
1 | 5 | 52 | 214 | 570 | 814 | 984 | 896 | 629 | 313 | 65 | 7 | 4418 |
| GDD Base 45 |
0 | 1 | 25 | 122 | 421 | 666 | 829 | 743 | 482 | 196 | 27 | 3 | 3411 |
| GDD Base 50 |
0 | 0 | 10 | 61 | 282 | 518 | 674 | 590 | 340 | 108 | 10 | 1 | 2516 |
| GDD Base 55 |
0 | 0 | 4 | 28 | 166 | 374 | 519 | 438 | 215 | 49 | 2 | 0 | 1741 |
| GDD Base 60 |
0 | 0 | 1 | 12 | 83 | 238 | 365 | 291 | 118 | 18 | 0 | 0 | 1092 |
| MGDD* Base 50 |
0 | 3 | 35 | 136 | 347 | 523 | 658 | 587 | 392 | 198 | 39 | 3 | 2837 |
| Date of Last Spring Occurrence | Date of First Fall Occurrence | |||||||||
| Base Temp °F |
Median | Early | 90% | 10% | Late | Median | Early | 90% | 10% | Late |
| 32 | 5/03 | 4/10 | 4/14 | 5/12 | 5/28 | 10/06 | 9/07 | 9/19 | 10/16 | 11/03 |
| 30 | 4/27 | 3/26 | 4/08 | 5/11 | 5/16 | 10/08 | 9/17 | 9/22 | 10/30 | 11/04 |
| 28 | 4/21 | 3/26 | 4/08 | 5/03 | 5/10 | 10/08 | 9/17 | 9/22 | 10/31 | 11/05 |
| 24 | 4/08 | 3/24 | 3/27 | 4/22 | 5/09 | 10/25 | 9/24 | 10/05 | 11/14 | 11/25 |
| 20 | 4/02 | 3/16 | 3/18 | 4/12 | 4/19 | 11/07 | 9/24 | 10/17 | 11/27 | 12/07 |
| 16 | 3/24 | 2/17 | 3/06 | 4/09 | 4/11 | 11/20 | 10/14 | 10/22 | 12/07 | 12/20 |
| Base Temp °F |
Median | Shortest | 10% | 90% | Longest |
| 32 | 156 | 119 | 130 | 180 | 203 |
| 30 | 162 | 138 | 142 | 201 | 212 |
| 28 | 169 | 139 | 152 | 203 | 212 |
| 24 | 203 | 140 | 175 | 224 | 231 |
| 20 | 217 | 166 | 205 | 247 | 266 |
| 16 | 245 | 195 | 209 | 279 | 280 |