Exeter Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Cassville. A median date has an even chance of a later freeze in spring, or an earlier one in fall.
The last spring freeze typically comes around April 14 and the first fall freeze around October 26, a growing season of about 194 days.
- Median at 36°F
- last April 26, first October 17
- Median at 32°F
- last April 14, first October 26
- Median at 28°F
- last April 3, first November 5
Last freeze in spring
The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 8 | May 4 | May 1 | Apr 29 | Apr 26 | Apr 22 | Apr 19 | Apr 15 | Apr 9 |
| 32°F | Apr 30 | Apr 25 | Apr 21 | Apr 17 | Apr 14 | Apr 11 | Apr 8 | Apr 3 | Mar 29 |
| 28°F | Apr 19 | Apr 14 | Apr 10 | Apr 7 | Apr 3 | Mar 31 | Mar 28 | Mar 23 | Mar 15 |
| 24°F | Apr 11 | Apr 5 | Mar 31 | Mar 28 | Mar 23 | Mar 18 | Mar 14 | Mar 8 | Mar 1 |
| 20°F | Mar 31 | Mar 24 | Mar 18 | Mar 14 | Mar 10 | Mar 6 | Mar 3 | Feb 28 | Feb 21 |
| 16°F | Mar 19 | Mar 13 | Mar 8 | Mar 4 | Mar 1 | Feb 26 | Feb 23 | Feb 17 | Feb 10 |
First freeze in fall
The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 1 | Oct 5 | Oct 9 | Oct 13 | Oct 17 | Oct 20 | Oct 23 | Oct 27 | Nov 1 |
| 32°F | Oct 11 | Oct 16 | Oct 20 | Oct 23 | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 10 |
| 28°F | Oct 20 | Oct 26 | Oct 30 | Nov 2 | Nov 5 | Nov 7 | Nov 10 | Nov 15 | Nov 19 |
| 24°F | Oct 30 | Nov 3 | Nov 7 | Nov 10 | Nov 14 | Nov 17 | Nov 20 | Nov 25 | Nov 30 |
| 20°F | Nov 7 | Nov 12 | Nov 16 | Nov 20 | Nov 23 | Nov 28 | Dec 1 | Dec 5 | Dec 10 |
| 16°F | Nov 16 | Nov 22 | Nov 27 | Dec 1 | Dec 4 | Dec 7 | Dec 12 | Dec 18 | Dec 25 |
Growing season length
Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | 195 | 188 | 183 | 178 | 173 | 169 | 165 | 160 | 153 |
| 32°F | 215 | 208 | 203 | 198 | 194 | 190 | 185 | 179 | 173 |
| 28°F | 236 | 228 | 223 | 218 | 214 | 209 | 205 | 199 | 192 |
| 24°F | 260 | 252 | 245 | 240 | 235 | 230 | 224 | 217 | 208 |
| 20°F | 279 | 272 | 267 | 263 | 257 | 251 | 245 | 238 | 228 |
| 16°F | 306 | 297 | 289 | 282 | 277 | 272 | 267 | 261 | 252 |
How often it gets that cold
The share of years with at least one night at or below each temperature.
- 36°F or colder
- 100% of years
- 32°F or colder
- 100% of years
- 28°F or colder
- 100% of years
- 24°F or colder
- 100% of years
- 20°F or colder
- 100% of years
- 16°F or colder
- 100% of years
Degree days
A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.
- Heating degree days, base 65°F
- 4,518
- Cooling degree days, base 65°F
- 1,212
- Growing degree days, base 40°F
- 6,532
- Growing degree days, base 45°F
- 5,176
- Growing degree days, base 50°F
- 3,961
- Growing degree days, base 55°F
- 2,898
- Growing degree days, base 60°F
- 1,979
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 979 | 0 | 9 |
| February | 767 | 0 | 19 |
| March | 579 | 5 | 88 |
| April | 308 | 20 | 217 |
| May | 113 | 88 | 445 |
| June | 10 | 232 | 672 |
| July | 1 | 360 | 824 |
| August | 3 | 335 | 796 |
| September | 55 | 139 | 536 |
| October | 256 | 30 | 269 |
| November | 570 | 3 | 73 |
| December | 877 | 0 | 13 |
What this means
NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.
The station is 6.6 km from Exeter. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.
More
Sources
NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00231383 (Cassville). Public domain.