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 | 17 | 139 | 452 | 687 | 843 | 780 | 487 | 192 | 26 | 1 | 3509 |
| GDD Base 45 |
0 | 0 | 5 | 73 | 310 | 537 | 688 | 625 | 343 | 101 | 9 | 0 | 2602 |
| GDD Base 50 |
0 | 0 | 1 | 34 | 191 | 390 | 534 | 471 | 215 | 43 | 2 | 0 | 1815 |
| GDD Base 55 |
0 | 0 | 0 | 15 | 103 | 254 | 381 | 320 | 116 | 14 | 0 | 0 | 1159 |
| GDD Base 60 |
0 | 0 | 0 | 5 | 46 | 139 | 235 | 184 | 50 | 3 | 0 | 0 | 638 |
| MGDD* Base 50 |
0 | 1 | 17 | 117 | 309 | 439 | 543 | 499 | 299 | 126 | 17 | 0 | 2294 |
| Date of Last Spring Occurrence | Date of First Fall Occurrence | |||||||||
| Base Temp °F |
Median | Early | 90% | 10% | Late | Median | Early | 90% | 10% | Late |
| 32 | 5/29 | 5/03 | 5/13 | 6/20 | 7/05 | 9/20 | 8/27 | 9/03 | 10/04 | 10/08 |
| 30 | 5/26 | 4/28 | 5/04 | 6/12 | 7/05 | 9/24 | 9/03 | 9/09 | 10/04 | 10/12 |
| 28 | 5/16 | 4/25 | 5/03 | 5/27 | 6/11 | 9/26 | 9/03 | 9/17 | 10/13 | 10/21 |
| 24 | 4/27 | 4/06 | 4/10 | 5/12 | 5/20 | 10/13 | 9/23 | 9/27 | 11/02 | 11/07 |
| 20 | 4/14 | 3/24 | 4/03 | 4/25 | 5/07 | 11/01 | 9/23 | 10/10 | 11/15 | 11/30 |
| 16 | 4/10 | 3/13 | 3/24 | 4/19 | 4/26 | 11/08 | 10/19 | 10/31 | 11/24 | 11/30 |
| Base Temp °F |
Median | Shortest | 10% | 90% | Longest |
| 32 | 116 | 61 | 90 | 132 | 140 |
| 30 | 126 | 80 | 103 | 140 | 149 |
| 28 | 135 | 104 | 115 | 155 | 176 |
| 24 | 169 | 126 | 144 | 191 | 206 |
| 20 | 198 | 139 | 174 | 222 | 234 |
| 16 | 216 | 176 | 200 | 234 | 261 |