Paint Rock Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Paint Rock. 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 March 30 and the first fall freeze around November 5, a growing season of about 222 days.
- Median at 36°F
- last April 9, first October 30
- Median at 32°F
- last March 30, first November 5
- Median at 28°F
- last March 14, first November 16
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 | Apr 25 | Apr 20 | Apr 16 | Apr 13 | Apr 9 | Apr 6 | Apr 3 | Mar 31 | Mar 23 |
| 32°F | Apr 17 | Apr 10 | Apr 6 | Apr 2 | Mar 30 | Mar 24 | Mar 19 | Mar 14 | Mar 7 |
| 28°F | Apr 2 | Mar 28 | Mar 22 | Mar 17 | Mar 14 | Mar 11 | Mar 6 | Mar 2 | Feb 26 |
| 24°F | Mar 20 | Mar 13 | Mar 9 | Mar 5 | Mar 2 | Feb 27 | Feb 24 | Feb 19 | Feb 8 |
| 20°F | Mar 10 | Mar 4 | Feb 28 | Feb 22 | Feb 18 | Feb 11 | Feb 3 | Jan 27 | Jan 14 |
| 16°F | Mar 3 | Feb 21 | Feb 12 | Feb 6 | Jan 30 | Jan 23 | Jan 15 | Jan 4 | Dec 23 |
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 17 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 11 |
| 32°F | Oct 24 | Oct 29 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 11 | Nov 15 | Nov 22 |
| 28°F | Nov 1 | Nov 5 | Nov 9 | Nov 12 | Nov 16 | Nov 19 | Nov 23 | Nov 28 | Dec 3 |
| 24°F | Nov 9 | Nov 14 | Nov 19 | Nov 23 | Nov 27 | Dec 1 | Dec 4 | Dec 8 | Dec 18 |
| 20°F | Nov 20 | Nov 26 | Dec 1 | Dec 4 | Dec 9 | Dec 15 | Dec 21 | Dec 28 | Jan 6 |
| 16°F | Dec 1 | Dec 6 | Dec 14 | Dec 20 | Dec 27 | Jan 2 | Jan 8 | Jan 18 | Feb 5 |
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 | 224 | 215 | 209 | 205 | 201 | 197 | 192 | 187 | 180 |
| 32°F | 246 | 238 | 232 | 226 | 222 | 217 | 213 | 207 | 200 |
| 28°F | 272 | 263 | 256 | 250 | 245 | 240 | 234 | 229 | 221 |
| 24°F | 299 | 289 | 282 | 275 | 269 | 264 | 257 | 251 | 242 |
| 20°F | 339 | 325 | 315 | 306 | 300 | 293 | 286 | 277 | 265 |
| 16°F | 365 | 364 | 353 | 344 | 336 | 329 | 321 | 310 | 298 |
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
- 98% of years
- 16°F or colder
- 84% 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
- 2,462
- Cooling degree days, base 65°F
- 2,518
- Growing degree days, base 40°F
- 9,328
- Growing degree days, base 45°F
- 7,683
- Growing degree days, base 50°F
- 6,160
- Growing degree days, base 55°F
- 4,788
- Growing degree days, base 60°F
- 3,573
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 616 | 0 | 54 |
| February | 448 | 3 | 94 |
| March | 276 | 22 | 256 |
| April | 96 | 105 | 465 |
| May | 14 | 289 | 741 |
| June | 0 | 476 | 925 |
| July | 0 | 581 | 1,046 |
| August | 0 | 566 | 1,031 |
| September | 7 | 343 | 786 |
| October | 83 | 117 | 505 |
| November | 333 | 15 | 196 |
| December | 589 | 1 | 62 |
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 1 km from Paint Rock. 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 USC00416747 (Paint Rock). Public domain.