Graford Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Mineral Wells AP. 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 24 and the first fall freeze around November 10, a growing season of about 231 days.
- Median at 36°F
- last April 6, first November 1
- Median at 32°F
- last March 24, first November 10
- Median at 28°F
- last March 9, first November 21
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 23 | Apr 18 | Apr 14 | Apr 9 | Apr 6 | Apr 3 | Mar 31 | Mar 25 | Mar 17 |
| 32°F | Apr 14 | Apr 6 | Apr 2 | Mar 29 | Mar 24 | Mar 19 | Mar 14 | Mar 10 | Mar 3 |
| 28°F | Apr 2 | Mar 24 | Mar 17 | Mar 13 | Mar 9 | Mar 4 | Feb 28 | Feb 24 | Feb 16 |
| 24°F | Mar 15 | Mar 9 | Mar 4 | Feb 28 | Feb 24 | Feb 18 | Feb 11 | Feb 3 | Jan 27 |
| 20°F | Mar 3 | Feb 25 | Feb 16 | Feb 10 | Feb 5 | Jan 31 | Jan 25 | Jan 18 | Jan 4 |
| 16°F | Feb 18 | Feb 7 | Feb 1 | Jan 26 | Jan 20 | Jan 12 | Jan 4 | Dec 26 | Dec 17 |
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 19 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 9 | Nov 16 |
| 32°F | Oct 27 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 21 | Nov 27 |
| 28°F | Nov 4 | Nov 9 | Nov 13 | Nov 17 | Nov 21 | Nov 24 | Nov 28 | Dec 2 | Dec 7 |
| 24°F | Nov 12 | Nov 19 | Nov 25 | Nov 29 | Dec 3 | Dec 6 | Dec 11 | Dec 17 | Dec 27 |
| 20°F | Nov 26 | Dec 2 | Dec 8 | Dec 13 | Dec 20 | Dec 27 | Jan 1 | Jan 7 | Jan 22 |
| 16°F | Dec 7 | Dec 14 | Dec 20 | Dec 27 | Jan 2 | Jan 6 | Jan 13 | Jan 21 | Feb 3 |
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 | 232 | 224 | 219 | 214 | 210 | 205 | 200 | 194 | 186 |
| 32°F | 258 | 248 | 242 | 235 | 231 | 226 | 219 | 213 | 206 |
| 28°F | 283 | 274 | 267 | 262 | 256 | 250 | 245 | 239 | 229 |
| 24°F | 317 | 305 | 297 | 289 | 282 | 277 | 272 | 264 | 254 |
| 20°F | 355 | 341 | 334 | 327 | 319 | 311 | 302 | 293 | 281 |
| 16°F | 365 | 365 | 365 | 361 | 353 | 346 | 339 | 330 | 313 |
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
- 94% of years
- 16°F or colder
- 67% 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
- 2,410
- Cooling degree days, base 65°F
- 2,489
- Growing degree days, base 40°F
- 9,339
- Growing degree days, base 45°F
- 7,687
- Growing degree days, base 50°F
- 6,163
- Growing degree days, base 55°F
- 4,785
- Growing degree days, base 60°F
- 3,557
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 609 | 1 | 60 |
| February | 435 | 7 | 111 |
| March | 260 | 35 | 278 |
| April | 98 | 95 | 452 |
| May | 16 | 256 | 705 |
| June | 0 | 449 | 898 |
| July | 0 | 581 | 1,046 |
| August | 0 | 573 | 1,038 |
| September | 6 | 348 | 792 |
| October | 91 | 122 | 502 |
| November | 319 | 19 | 210 |
| December | 576 | 2 | 71 |
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 24.6 km from Graford. 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 USW00093985 (Mineral Wells AP). Public domain.