Wheelwright Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Clintwood 1W. 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 29 and the first fall freeze around October 16, a growing season of about 169 days.
- Median at 36°F
- last May 9, first October 8
- Median at 32°F
- last April 29, first October 16
- Median at 28°F
- last April 15, first October 26
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 26 | May 20 | May 15 | May 12 | May 9 | May 6 | May 2 | Apr 30 | Apr 25 |
| 32°F | May 15 | May 9 | May 5 | May 1 | Apr 29 | Apr 26 | Apr 22 | Apr 19 | Apr 15 |
| 28°F | May 3 | Apr 26 | Apr 21 | Apr 18 | Apr 15 | Apr 12 | Apr 8 | Apr 4 | Apr 1 |
| 24°F | Apr 14 | Apr 10 | Apr 6 | Apr 3 | Apr 1 | Mar 30 | Mar 26 | Mar 22 | Mar 16 |
| 20°F | Apr 3 | Mar 30 | Mar 26 | Mar 22 | Mar 18 | Mar 15 | Mar 11 | Mar 7 | Feb 28 |
| 16°F | Mar 23 | Mar 19 | Mar 14 | Mar 9 | Mar 5 | Feb 28 | Feb 24 | Feb 16 | Feb 8 |
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 27 | Oct 1 | Oct 4 | Oct 6 | Oct 8 | Oct 10 | Oct 12 | Oct 15 | Oct 20 |
| 32°F | Oct 4 | Oct 9 | Oct 11 | Oct 14 | Oct 16 | Oct 19 | Oct 22 | Oct 25 | Nov 1 |
| 28°F | Oct 13 | Oct 17 | Oct 20 | Oct 24 | Oct 26 | Oct 29 | Nov 1 | Nov 3 | Nov 7 |
| 24°F | Oct 22 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 14 | Nov 19 |
| 20°F | Nov 1 | Nov 5 | Nov 10 | Nov 13 | Nov 16 | Nov 19 | Nov 23 | Nov 28 | Dec 4 |
| 16°F | Nov 12 | Nov 18 | Nov 23 | Nov 28 | Dec 1 | Dec 4 | Dec 10 | Dec 16 | Dec 26 |
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 | 172 | 164 | 159 | 155 | 151 | 147 | 142 | 137 | 131 |
| 32°F | 190 | 183 | 178 | 174 | 169 | 165 | 161 | 156 | 149 |
| 28°F | 211 | 205 | 200 | 196 | 192 | 188 | 183 | 178 | 171 |
| 24°F | 238 | 231 | 225 | 220 | 217 | 212 | 208 | 203 | 196 |
| 20°F | 268 | 260 | 254 | 247 | 243 | 238 | 233 | 226 | 220 |
| 16°F | 301 | 291 | 284 | 277 | 270 | 264 | 258 | 252 | 243 |
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
- 5,174
- Cooling degree days, base 65°F
- 592
- Growing degree days, base 40°F
- 5,408
- Growing degree days, base 45°F
- 4,125
- Growing degree days, base 50°F
- 3,007
- Growing degree days, base 55°F
- 2,043
- Growing degree days, base 60°F
- 1,235
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,020 | 0 | 6 |
| February | 832 | 0 | 8 |
| March | 693 | 0 | 40 |
| April | 379 | 5 | 154 |
| May | 162 | 37 | 349 |
| June | 30 | 111 | 531 |
| July | 5 | 199 | 659 |
| August | 7 | 171 | 629 |
| September | 83 | 64 | 432 |
| October | 373 | 6 | 162 |
| November | 674 | 0 | 29 |
| December | 918 | 0 | 9 |
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 29.1 km from Wheelwright. 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 USC00441825 (Clintwood 1W). Public domain.