Clayton Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Tuskahoma. 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 11 and the first fall freeze around October 27, a growing season of about 199 days.
- Median at 36°F
- last April 21, first October 18
- Median at 32°F
- last April 11, first October 27
- Median at 28°F
- last March 31, first November 4
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 5 | Apr 30 | Apr 27 | Apr 24 | Apr 21 | Apr 18 | Apr 15 | Apr 11 | Apr 5 |
| 32°F | Apr 27 | Apr 22 | Apr 18 | Apr 14 | Apr 11 | Apr 8 | Apr 4 | Mar 31 | Mar 25 |
| 28°F | Apr 19 | Apr 11 | Apr 6 | Apr 2 | Mar 31 | Mar 28 | Mar 23 | Mar 16 | Mar 9 |
| 24°F | Apr 5 | Mar 30 | Mar 24 | Mar 20 | Mar 16 | Mar 11 | Mar 6 | Mar 1 | Feb 24 |
| 20°F | Mar 23 | Mar 17 | Mar 12 | Mar 7 | Mar 3 | Feb 27 | Feb 22 | Feb 15 | Feb 1 |
| 16°F | Mar 12 | Mar 4 | Feb 28 | Feb 21 | Feb 14 | Feb 7 | Jan 31 | Jan 26 | Jan 15 |
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 2 | Oct 7 | Oct 11 | Oct 14 | Oct 18 | Oct 21 | Oct 24 | Oct 28 | Nov 1 |
| 32°F | Oct 12 | Oct 17 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 5 | Nov 9 |
| 28°F | Oct 18 | Oct 25 | Oct 29 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 16 | Nov 24 |
| 24°F | Oct 28 | Nov 2 | Nov 6 | Nov 10 | Nov 15 | Nov 20 | Nov 25 | Dec 1 | Dec 6 |
| 20°F | Nov 5 | Nov 13 | Nov 20 | Nov 26 | Dec 1 | Dec 4 | Dec 8 | Dec 14 | Dec 25 |
| 16°F | Nov 20 | Nov 29 | Dec 3 | Dec 9 | Dec 15 | Dec 21 | Dec 28 | Jan 4 | Jan 14 |
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 | 204 | 196 | 190 | 185 | 181 | 177 | 173 | 166 | 159 |
| 32°F | 226 | 215 | 209 | 204 | 199 | 193 | 190 | 184 | 176 |
| 28°F | 249 | 239 | 232 | 226 | 220 | 215 | 209 | 203 | 195 |
| 24°F | 278 | 267 | 259 | 253 | 246 | 240 | 233 | 227 | 217 |
| 20°F | 309 | 296 | 289 | 281 | 275 | 268 | 262 | 254 | 242 |
| 16°F | 343 | 330 | 320 | 312 | 306 | 299 | 292 | 281 | 270 |
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
- 98% 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
- 3,303
- Cooling degree days, base 65°F
- 1,903
- Growing degree days, base 40°F
- 8,023
- Growing degree days, base 45°F
- 6,498
- Growing degree days, base 50°F
- 5,124
- Growing degree days, base 55°F
- 3,902
- Growing degree days, base 60°F
- 2,824
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 768 | 0 | 29 |
| February | 582 | 2 | 52 |
| March | 404 | 10 | 160 |
| April | 187 | 44 | 325 |
| May | 43 | 159 | 582 |
| June | 2 | 348 | 796 |
| July | 0 | 511 | 976 |
| August | 0 | 481 | 945 |
| September | 20 | 266 | 696 |
| October | 164 | 71 | 386 |
| November | 435 | 9 | 136 |
| December | 699 | 1 | 41 |
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 7.2 km from Clayton. 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 USC00349023 (Tuskahoma). Public domain.