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 | 1 | 27 | 165 | 468 | 680 | 831 | 765 | 496 | 218 | 27 | 1 | 3591 |
| GDD Base 45 |
0 | 0 | 11 | 90 | 324 | 531 | 677 | 613 | 353 | 122 | 9 | 0 | 2661 |
| GDD Base 50 |
0 | 0 | 4 | 44 | 201 | 385 | 523 | 461 | 227 | 59 | 3 | 0 | 1856 |
| GDD Base 55 |
0 | 0 | 0 | 20 | 110 | 249 | 370 | 314 | 130 | 23 | 0 | 0 | 1184 |
| GDD Base 60 |
0 | 0 | 0 | 8 | 50 | 136 | 226 | 182 | 64 | 7 | 0 | 0 | 654 |
| MGDD* Base 50 |
0 | 1 | 19 | 121 | 311 | 439 | 545 | 496 | 311 | 136 | 16 | 0 | 2340 |
| Date of Last Spring Occurrence | Date of First Fall Occurrence | |||||||||
| Base Temp °F |
Median | Early | 90% | 10% | Late | Median | Early | 90% | 10% | Late |
| 32 | 6/07 | 5/03 | 5/20 | 6/21 | 7/13 | 9/12 | 8/02 | 8/16 | 9/23 | 10/03 |
| 30 | 5/28 | 5/01 | 5/11 | 6/20 | 7/05 | 9/22 | 8/02 | 8/18 | 10/01 | 10/09 |
| 28 | 5/21 | 4/27 | 4/29 | 6/14 | 7/05 | 9/23 | 8/16 | 9/05 | 10/09 | 10/22 |
| 24 | 5/03 | 4/03 | 4/11 | 5/23 | 6/11 | 10/04 | 8/24 | 9/21 | 10/29 | 11/02 |
| 20 | 4/20 | 3/24 | 4/03 | 5/06 | 5/09 | 10/15 | 9/03 | 9/28 | 11/04 | 11/08 |
| 16 | 4/09 | 3/20 | 3/23 | 4/23 | 5/02 | 10/30 | 9/29 | 10/12 | 11/15 | 11/21 |
| Base Temp °F |
Median | Shortest | 10% | 90% | Longest |
| 32 | 96 | 20 | 67 | 122 | 140 |
| 30 | 113 | 31 | 72 | 139 | 143 |
| 28 | 124 | 70 | 90 | 152 | 172 |
| 24 | 160 | 107 | 120 | 184 | 194 |
| 20 | 183 | 120 | 147 | 211 | 224 |
| 16 | 203 | 161 | 180 | 224 | 246 |