McCleary Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Matlock 8 S. 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 23 and the first fall freeze around October 20, a growing season of about 183 days.
- Median at 36°F
- last May 10, first October 2
- Median at 32°F
- last April 23, first October 20
- Median at 28°F
- last March 23, first November 10
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 | Jun 2 | May 25 | May 19 | May 14 | May 10 | May 6 | May 3 | Apr 30 | Apr 26 |
| 32°F | May 7 | May 2 | Apr 29 | Apr 27 | Apr 23 | Apr 19 | Apr 14 | Apr 7 | Apr 1 |
| 28°F | Apr 19 | Apr 9 | Apr 2 | Mar 28 | Mar 23 | Mar 16 | Mar 10 | Feb 28 | Feb 22 |
| 24°F | Mar 16 | Mar 4 | Feb 28 | Feb 22 | Feb 15 | Feb 8 | Jan 24 | Jan 3 | Dec 15 |
| 20°F | Feb 25 | Feb 17 | Feb 10 | Jan 31 | Jan 14 | Dec 31 | Dec 18 | Dec 9 | Dec 1 |
| 16°F | Feb 18 | Feb 4 | Jan 22 | Jan 1 | Dec 27 | Dec 19 | Dec 12 | Dec 6 | Dec 1 |
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 15 | Sep 21 | Sep 25 | Sep 30 | Oct 2 | Oct 5 | Oct 9 | Oct 15 | Oct 21 |
| 32°F | Oct 1 | Oct 5 | Oct 10 | Oct 15 | Oct 20 | Oct 24 | Oct 27 | Nov 1 | Nov 10 |
| 28°F | Oct 17 | Oct 24 | Oct 30 | Nov 5 | Nov 10 | Nov 16 | Nov 22 | Nov 29 | Dec 12 |
| 24°F | Nov 5 | Nov 13 | Nov 22 | Nov 28 | Dec 3 | Dec 10 | Dec 19 | Dec 31 | Jan 27 |
| 20°F | Nov 22 | Dec 1 | Dec 6 | Dec 13 | Dec 21 | Dec 31 | Jan 13 | Feb 1 | Feb 16 |
| 16°F | Nov 30 | Dec 5 | Dec 9 | Dec 15 | Dec 21 | Dec 29 | Jan 1 | Jan 29 | Feb 16 |
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 | 170 | 160 | 153 | 148 | 142 | 137 | 130 | 124 | 114 |
| 32°F | 212 | 203 | 195 | 189 | 183 | 177 | 172 | 165 | 156 |
| 28°F | 275 | 263 | 252 | 243 | 236 | 228 | 219 | 208 | 198 |
| 24°F | 349 | 332 | 319 | 311 | 303 | 291 | 280 | 269 | 254 |
| 20°F | 365 | 365 | 365 | 365 | 353 | 338 | 329 | 317 | 304 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 363 | 336 |
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
- 94% of years
- 20°F or colder
- 59% of years
- 16°F or colder
- 22% 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
- 5,155
- Cooling degree days, base 65°F
- 103
- Growing degree days, base 40°F
- 4,265
- Growing degree days, base 45°F
- 2,850
- Growing degree days, base 50°F
- 1,770
- Growing degree days, base 55°F
- 970
- Growing degree days, base 60°F
- 401
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 749 | 0 | 1 |
| February | 651 | 0 | 1 |
| March | 632 | 0 | 8 |
| April | 486 | 0 | 38 |
| May | 307 | 2 | 173 |
| June | 178 | 13 | 286 |
| July | 64 | 42 | 443 |
| August | 59 | 40 | 446 |
| September | 175 | 6 | 282 |
| October | 436 | 0 | 80 |
| November | 627 | 0 | 11 |
| December | 790 | 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 14.5 km from McCleary. 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 USC00455086 (Matlock 8 S). Public domain.