Stoddard Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Genoa Dam 8. 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 22 and the first fall freeze around October 17, a growing season of about 178 days.
- Median at 36°F
- last May 2, first October 7
- Median at 32°F
- last April 22, first October 17
- Median at 28°F
- last April 10, first October 28
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 15 | May 10 | May 7 | May 5 | May 2 | Apr 30 | Apr 28 | Apr 24 | Apr 19 |
| 32°F | May 5 | May 1 | Apr 28 | Apr 24 | Apr 22 | Apr 19 | Apr 15 | Apr 11 | Apr 6 |
| 28°F | Apr 24 | Apr 20 | Apr 16 | Apr 12 | Apr 10 | Apr 7 | Apr 4 | Apr 2 | Mar 29 |
| 24°F | Apr 15 | Apr 9 | Apr 6 | Apr 4 | Apr 2 | Mar 31 | Mar 28 | Mar 24 | Mar 18 |
| 20°F | Apr 7 | Apr 3 | Mar 31 | Mar 27 | Mar 24 | Mar 21 | Mar 18 | Mar 15 | Mar 10 |
| 16°F | Apr 1 | Mar 26 | Mar 23 | Mar 20 | Mar 17 | Mar 15 | Mar 12 | Mar 8 | Mar 3 |
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 | Sep 23 | Sep 29 | Oct 2 | Oct 5 | Oct 7 | Oct 9 | Oct 12 | Oct 15 | Oct 21 |
| 32°F | Oct 4 | Oct 8 | Oct 12 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Oct 31 |
| 28°F | Oct 13 | Oct 19 | Oct 22 | Oct 25 | Oct 28 | Oct 30 | Nov 1 | Nov 4 | Nov 9 |
| 24°F | Oct 26 | Oct 31 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 17 | Nov 21 |
| 20°F | Nov 3 | Nov 5 | Nov 9 | Nov 13 | Nov 16 | Nov 18 | Nov 21 | Nov 24 | Nov 30 |
| 16°F | Nov 9 | Nov 14 | Nov 18 | Nov 20 | Nov 23 | Nov 26 | Nov 30 | Dec 4 | Dec 10 |
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 | 175 | 169 | 164 | 160 | 157 | 153 | 150 | 145 | 139 |
| 32°F | 199 | 192 | 187 | 182 | 178 | 174 | 171 | 165 | 159 |
| 28°F | 218 | 212 | 207 | 203 | 200 | 196 | 192 | 187 | 180 |
| 24°F | 238 | 231 | 226 | 222 | 219 | 215 | 211 | 206 | 199 |
| 20°F | 256 | 250 | 245 | 241 | 236 | 232 | 228 | 224 | 217 |
| 16°F | 271 | 265 | 260 | 255 | 251 | 247 | 243 | 238 | 231 |
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
- 6,814
- Cooling degree days, base 65°F
- 835
- Growing degree days, base 40°F
- 5,149
- Growing degree days, base 45°F
- 4,054
- Growing degree days, base 50°F
- 3,071
- Growing degree days, base 55°F
- 2,199
- Growing degree days, base 60°F
- 1,450
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,423 | 0 | 0 |
| February | 1,170 | 0 | 0 |
| March | 914 | 1 | 18 |
| April | 491 | 5 | 98 |
| May | 189 | 49 | 337 |
| June | 26 | 182 | 606 |
| July | 3 | 280 | 742 |
| August | 8 | 223 | 680 |
| September | 108 | 85 | 431 |
| October | 427 | 9 | 141 |
| November | 824 | 0 | 17 |
| December | 1,232 | 0 | 1 |
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 10.2 km from Stoddard. 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 USC00473038 (Genoa Dam 8). Public domain.