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 | 4 | 56 | 222 | 552 | 804 | 951 | 881 | 619 | 301 | 61 | 5 | 4390 |
| GDD Base 45 |
0 | 1 | 28 | 128 | 403 | 655 | 799 | 729 | 473 | 186 | 27 | 2 | 3380 |
| GDD Base 50 |
0 | 0 | 12 | 65 | 266 | 507 | 647 | 577 | 332 | 101 | 10 | 0 | 2484 |
| GDD Base 55 |
0 | 0 | 5 | 30 | 154 | 362 | 494 | 425 | 208 | 45 | 2 | 0 | 1707 |
| GDD Base 60 |
0 | 0 | 1 | 12 | 76 | 227 | 343 | 277 | 112 | 15 | 0 | 0 | 1058 |
| MGDD* Base 50 |
0 | 2 | 36 | 136 | 328 | 513 | 634 | 576 | 372 | 176 | 34 | 2 | 2772 |
| 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 | 3/27 | 4/14 | 5/23 | 5/29 | 10/06 | 9/17 | 9/22 | 10/25 | 11/01 |
| 30 | 4/22 | 3/27 | 4/09 | 5/10 | 5/29 | 10/12 | 9/17 | 9/22 | 11/04 | 11/04 |
| 28 | 4/18 | 3/24 | 4/07 | 5/07 | 5/10 | 10/13 | 9/22 | 9/29 | 11/04 | 11/13 |
| 24 | 4/09 | 3/23 | 3/29 | 4/22 | 4/28 | 11/01 | 9/26 | 10/16 | 11/17 | 11/29 |
| 20 | 4/04 | 3/07 | 3/16 | 4/13 | 4/22 | 11/07 | 10/08 | 10/20 | 11/24 | 12/21 |
| 16 | 3/25 | 2/18 | 3/03 | 4/09 | 4/11 | 11/16 | 11/02 | 11/05 | 12/06 | 12/21 |
| Base Temp °F |
Median | Shortest | 10% | 90% | Longest |
| 32 | 156 | 111 | 129 | 186 | 201 |
| 30 | 171 | 111 | 137 | 207 | 213 |
| 28 | 178 | 139 | 153 | 210 | 225 |
| 24 | 203 | 172 | 179 | 226 | 248 |
| 20 | 217 | 187 | 193 | 255 | 279 |
| 16 | 234 | 206 | 214 | 279 | 282 |