Kinney County Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Brackettville. 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 5 and the first fall freeze around November 24, a growing season of about 264 days.
- Median at 36°F
- last March 18, first November 12
- Median at 32°F
- last March 5, first November 24
- Median at 28°F
- last February 16, first December 6
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 5 | Mar 31 | Mar 26 | Mar 22 | Mar 18 | Mar 13 | Mar 8 | Mar 4 | Feb 26 |
| 32°F | Mar 26 | Mar 19 | Mar 14 | Mar 9 | Mar 5 | Mar 1 | Feb 24 | Feb 17 | Feb 7 |
| 28°F | Mar 15 | Mar 7 | Mar 1 | Feb 23 | Feb 16 | Feb 10 | Feb 3 | Jan 27 | Jan 17 |
| 24°F | Mar 4 | Feb 18 | Feb 8 | Feb 2 | Jan 27 | Jan 20 | Jan 14 | Jan 4 | Dec 22 |
| 20°F | Feb 18 | Feb 3 | Jan 27 | Jan 20 | Jan 14 | Jan 8 | Jan 2 | Dec 27 | Dec 16 |
| 16°F | Feb 2 | Jan 21 | Jan 17 | Jan 12 | Jan 8 | Jan 4 | Dec 31 | Dec 26 | Dec 21 |
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 28 | Nov 1 | Nov 5 | Nov 9 | Nov 12 | Nov 16 | Nov 21 | Nov 26 | Dec 2 |
| 32°F | Nov 3 | Nov 9 | Nov 15 | Nov 20 | Nov 24 | Nov 29 | Dec 4 | Dec 9 | Dec 15 |
| 28°F | Nov 12 | Nov 21 | Nov 27 | Dec 2 | Dec 6 | Dec 11 | Dec 18 | Dec 26 | Jan 5 |
| 24°F | Nov 26 | Dec 4 | Dec 11 | Dec 17 | Dec 24 | Dec 30 | Jan 4 | Jan 11 | Jan 28 |
| 20°F | Dec 6 | Dec 15 | Dec 22 | Dec 29 | Jan 2 | Jan 7 | Jan 11 | Jan 18 | Feb 1 |
| 16°F | Dec 17 | Dec 23 | Dec 27 | Jan 2 | Jan 6 | Jan 10 | Jan 13 | Jan 18 | Jan 23 |
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 | 268 | 258 | 251 | 245 | 239 | 234 | 228 | 221 | 212 |
| 32°F | 294 | 283 | 276 | 271 | 264 | 259 | 252 | 245 | 234 |
| 28°F | 331 | 317 | 307 | 299 | 291 | 284 | 278 | 270 | 258 |
| 24°F | 365 | 356 | 346 | 338 | 329 | 321 | 313 | 303 | 290 |
| 20°F | 365 | 365 | 365 | 365 | 363 | 355 | 347 | 338 | 324 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 364 | 351 |
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
- 99% of years
- 24°F or colder
- 87% of years
- 20°F or colder
- 50% of years
- 16°F or colder
- 19% 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
- 1,506
- Cooling degree days, base 65°F
- 2,985
- Growing degree days, base 40°F
- 10,634
- Growing degree days, base 45°F
- 8,871
- Growing degree days, base 50°F
- 7,188
- Growing degree days, base 55°F
- 5,629
- Growing degree days, base 60°F
- 4,222
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 436 | 3 | 124 |
| February | 279 | 15 | 198 |
| March | 134 | 75 | 417 |
| April | 34 | 169 | 586 |
| May | 5 | 363 | 823 |
| June | 0 | 497 | 946 |
| July | 0 | 588 | 1,052 |
| August | 0 | 608 | 1,072 |
| September | 2 | 424 | 871 |
| October | 37 | 200 | 629 |
| November | 182 | 41 | 327 |
| December | 398 | 5 | 143 |
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 3.7 km from Kinney County. 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 USC00411007 (Brackettville). Public domain.