Bandera Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Medina 1NE. 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 16 and the first fall freeze around November 15, a growing season of about 244 days.
- Median at 36°F
- last April 2, first November 5
- Median at 32°F
- last March 16, first November 15
- Median at 28°F
- last March 2, first November 29
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 20 | Apr 13 | Apr 9 | Apr 5 | Apr 2 | Mar 30 | Mar 24 | Mar 18 | Mar 9 |
| 32°F | Apr 6 | Mar 31 | Mar 25 | Mar 20 | Mar 16 | Mar 10 | Mar 6 | Mar 1 | Feb 23 |
| 28°F | Mar 21 | Mar 14 | Mar 9 | Mar 5 | Mar 2 | Feb 25 | Feb 19 | Feb 13 | Feb 3 |
| 24°F | Mar 9 | Mar 4 | Feb 27 | Feb 19 | Feb 12 | Feb 5 | Jan 30 | Jan 22 | Jan 4 |
| 20°F | Mar 3 | Feb 20 | Feb 9 | Feb 2 | Jan 26 | Jan 18 | Jan 9 | Dec 31 | Dec 18 |
| 16°F | Feb 9 | Feb 2 | Jan 23 | Jan 20 | Jan 13 | Jan 5 | Dec 30 | Dec 25 | Dec 15 |
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 22 | Oct 27 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 12 | Nov 15 | Nov 22 |
| 32°F | Oct 31 | Nov 4 | Nov 8 | Nov 12 | Nov 15 | Nov 20 | Nov 24 | Nov 28 | Dec 3 |
| 28°F | Nov 7 | Nov 14 | Nov 20 | Nov 25 | Nov 29 | Dec 1 | Dec 5 | Dec 11 | Dec 20 |
| 24°F | Nov 21 | Nov 28 | Dec 3 | Dec 8 | Dec 13 | Dec 19 | Dec 26 | Jan 2 | Jan 15 |
| 20°F | Dec 2 | Dec 9 | Dec 17 | Dec 25 | Dec 30 | Jan 3 | Jan 12 | Jan 21 | Feb 9 |
| 16°F | Dec 9 | Dec 18 | Dec 26 | Jan 1 | Jan 5 | Jan 13 | Jan 19 | Jan 25 | Feb 6 |
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 | 244 | 234 | 228 | 222 | 217 | 212 | 207 | 200 | 191 |
| 32°F | 273 | 262 | 256 | 250 | 244 | 238 | 232 | 225 | 216 |
| 28°F | 305 | 292 | 284 | 277 | 272 | 266 | 260 | 253 | 244 |
| 24°F | 343 | 332 | 322 | 313 | 306 | 299 | 290 | 281 | 270 |
| 20°F | 365 | 365 | 360 | 351 | 343 | 334 | 326 | 313 | 299 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 365 | 364 | 351 | 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
- 96% of years
- 20°F or colder
- 72% of years
- 16°F or colder
- 32% 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
- 1,909
- Cooling degree days, base 65°F
- 2,515
- Growing degree days, base 40°F
- 9,783
- Growing degree days, base 45°F
- 8,057
- Growing degree days, base 50°F
- 6,439
- Growing degree days, base 55°F
- 4,962
- Growing degree days, base 60°F
- 3,648
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 497 | 3 | 91 |
| February | 348 | 7 | 145 |
| March | 199 | 38 | 325 |
| April | 70 | 103 | 485 |
| May | 10 | 287 | 742 |
| June | 0 | 457 | 907 |
| July | 0 | 535 | 1,000 |
| August | 0 | 539 | 1,004 |
| September | 3 | 362 | 808 |
| October | 61 | 152 | 559 |
| November | 250 | 28 | 263 |
| December | 471 | 5 | 109 |
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 19.3 km from Bandera. 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 USC00415742 (Medina 1NE). Public domain.