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 | 52 | 263 | 620 | 858 | 1023 | 951 | 664 | 335 | 56 | 3 | 4761 |
| GDD Base 45 |
0 | 1 | 22 | 157 | 467 | 708 | 868 | 797 | 515 | 210 | 23 | 1 | 3714 |
| GDD Base 50 |
0 | 0 | 7 | 83 | 321 | 558 | 713 | 643 | 370 | 114 | 8 | 0 | 2776 |
| GDD Base 55 |
0 | 0 | 2 | 38 | 195 | 410 | 559 | 489 | 238 | 52 | 2 | 0 | 1953 |
| GDD Base 60 |
0 | 0 | 0 | 14 | 101 | 268 | 404 | 337 | 132 | 18 | 0 | 0 | 1254 |
| MGDD* Base 50 |
0 | 2 | 28 | 153 | 371 | 560 | 697 | 636 | 400 | 179 | 28 | 1 | 3014 |
| Date of Last Spring Occurrence | Date of First Fall Occurrence | |||||||||
| Base Temp °F |
Median | Early | 90% | 10% | Late | Median | Early | 90% | 10% | Late |
| 32 | 4/22 | 4/04 | 4/09 | 5/11 | 5/17 | 10/06 | 9/20 | 9/25 | 11/01 | 11/03 |
| 30 | 4/19 | 3/24 | 4/06 | 5/05 | 5/11 | 10/14 | 9/20 | 9/29 | 11/01 | 11/04 |
| 28 | 4/13 | 3/23 | 3/28 | 5/05 | 5/10 | 10/21 | 9/20 | 10/02 | 11/03 | 11/09 |
| 24 | 4/06 | 3/21 | 3/24 | 4/17 | 5/06 | 11/03 | 10/02 | 10/21 | 11/13 | 11/22 |
| 20 | 3/29 | 3/07 | 3/17 | 4/11 | 4/13 | 11/12 | 10/20 | 10/30 | 11/25 | 12/20 |
| 16 | 3/19 | 2/26 | 3/07 | 4/07 | 4/09 | 11/20 | 11/01 | 11/05 | 12/11 | 12/20 |
| Base Temp °F |
Median | Shortest | 10% | 90% | Longest |
| 32 | 164 | 126 | 148 | 192 | 207 |
| 30 | 182 | 134 | 148 | 198 | 225 |
| 28 | 192 | 141 | 150 | 209 | 225 |
| 24 | 211 | 177 | 188 | 229 | 234 |
| 20 | 224 | 194 | 213 | 243 | 279 |
| 16 | 247 | 214 | 219 | 276 | 282 |