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 | 8 | 82 | 306 | 645 | 899 | 1058 | 997 | 715 | 393 | 85 | 7 | 5169 |
| GDD Base 45 |
0 | 1 | 41 | 192 | 491 | 750 | 903 | 842 | 566 | 260 | 40 | 2 | 4066 |
| GDD Base 50 |
0 | 0 | 19 | 106 | 344 | 600 | 749 | 687 | 420 | 154 | 15 | 0 | 3076 |
| GDD Base 55 |
0 | 0 | 8 | 52 | 216 | 451 | 594 | 533 | 284 | 79 | 4 | 0 | 2207 |
| GDD Base 60 |
0 | 0 | 2 | 24 | 118 | 307 | 439 | 378 | 171 | 32 | 1 | 0 | 1464 |
| MGDD* Base 50 |
0 | 5 | 56 | 195 | 403 | 593 | 712 | 668 | 454 | 240 | 48 | 3 | 3360 |
| Date of Last Spring Occurrence | Date of First Fall Occurrence | |||||||||
| Base Temp °F |
Median | Early | 90% | 10% | Late | Median | Early | 90% | 10% | Late |
| 32 | 5/02 | 4/04 | 4/19 | 5/14 | 5/16 | 10/05 | 9/19 | 9/23 | 10/15 | 10/20 |
| 30 | 4/22 | 3/26 | 4/05 | 5/09 | 5/16 | 10/09 | 9/22 | 9/25 | 10/30 | 11/01 |
| 28 | 4/16 | 3/24 | 3/31 | 5/02 | 5/10 | 10/18 | 9/22 | 10/02 | 11/03 | 11/03 |
| 24 | 4/09 | 3/19 | 3/24 | 4/20 | 5/06 | 10/31 | 10/02 | 10/13 | 11/11 | 11/13 |
| 20 | 4/03 | 3/06 | 3/19 | 4/11 | 4/18 | 11/09 | 10/20 | 10/25 | 11/21 | 11/29 |
| 16 | 3/21 | 2/22 | 3/05 | 4/08 | 4/11 | 11/17 | 10/31 | 11/07 | 12/02 | 12/20 |
| Base Temp °F |
Median | Shortest | 10% | 90% | Longest |
| 32 | 156 | 137 | 142 | 172 | 181 |
| 30 | 172 | 139 | 151 | 191 | 201 |
| 28 | 185 | 139 | 154 | 207 | 212 |
| 24 | 201 | 177 | 183 | 229 | 238 |
| 20 | 218 | 194 | 207 | 245 | 259 |
| 16 | 245 | 212 | 218 | 268 | 280 |