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 | 435 | 689 | 844 | 792 | 481 | 197 | 26 | 1 | 3394 |
| GDD Base 45 |
0 | 0 | 4 | 68 | 298 | 540 | 691 | 639 | 341 | 106 | 8 | 0 | 2549 |
| GDD Base 50 |
0 | 0 | 1 | 31 | 184 | 394 | 538 | 487 | 215 | 48 | 2 | 0 | 1808 |
| GDD Base 55 |
0 | 0 | 0 | 13 | 101 | 258 | 385 | 337 | 117 | 17 | 0 | 0 | 1177 |
| GDD Base 60 |
0 | 0 | 0 | 5 | 47 | 144 | 241 | 199 | 53 | 5 | 0 | 0 | 669 |
| MGDD* Base 50 |
0 | 1 | 16 | 103 | 288 | 434 | 544 | 504 | 289 | 124 | 17 | 1 | 2186 |
| 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 | 5/03 | 5/12 | 6/07 | 6/23 | 9/22 | 8/29 | 9/05 | 10/09 | 10/16 |
| 30 | 5/21 | 5/01 | 5/10 | 6/01 | 6/04 | 9/26 | 9/07 | 9/18 | 10/12 | 10/17 |
| 28 | 5/13 | 4/18 | 4/29 | 5/30 | 6/02 | 10/09 | 9/20 | 9/23 | 10/27 | 11/01 |
| 24 | 4/29 | 3/30 | 4/09 | 5/14 | 5/16 | 10/20 | 9/23 | 9/30 | 11/04 | 11/13 |
| 20 | 4/20 | 3/25 | 4/08 | 5/02 | 5/14 | 10/30 | 10/04 | 10/14 | 11/13 | 11/13 |
| 16 | 4/09 | 3/23 | 3/24 | 4/18 | 4/21 | 11/08 | 10/13 | 10/18 | 11/16 | 11/21 |
| Base Temp °F |
Median | Shortest | 10% | 90% | Longest |
| 32 | 123 | 81 | 101 | 147 | 148 |
| 30 | 130 | 97 | 114 | 150 | 158 |
| 28 | 154 | 119 | 127 | 168 | 183 |
| 24 | 178 | 135 | 155 | 200 | 207 |
| 20 | 195 | 159 | 167 | 207 | 217 |
| 16 | 215 | 179 | 191 | 223 | 236 |