Achille Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Durant 6SSE Mesonet. 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 19 and the first fall freeze around November 12, a growing season of about 237 days.
- Median at 36°F
- last April 2, first November 1
- Median at 32°F
- last March 19, first November 12
- Median at 28°F
- last March 5, first November 24
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 15 | Apr 9 | Apr 5 | Apr 2 | Mar 29 | Mar 25 | Mar 20 | Mar 13 |
| 32°F | Apr 7 | Apr 1 | Mar 27 | Mar 23 | Mar 19 | Mar 14 | Mar 10 | Mar 6 | Mar 1 |
| 28°F | Mar 24 | Mar 17 | Mar 13 | Mar 9 | Mar 5 | Mar 2 | Feb 26 | Feb 22 | Feb 12 |
| 24°F | Mar 12 | Mar 6 | Mar 2 | Feb 26 | Feb 20 | Feb 13 | Feb 7 | Jan 31 | Jan 21 |
| 20°F | Mar 4 | Feb 25 | Feb 17 | Feb 9 | Feb 3 | Jan 30 | Jan 24 | Jan 17 | Jan 3 |
| 16°F | Feb 21 | Feb 9 | Feb 2 | Jan 29 | Jan 22 | Jan 17 | Jan 8 | Jan 1 | 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 19 | Oct 23 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 12 | Nov 18 |
| 32°F | Oct 28 | Nov 1 | Nov 5 | Nov 8 | Nov 12 | Nov 16 | Nov 20 | Nov 26 | Dec 1 |
| 28°F | Nov 5 | Nov 10 | Nov 15 | Nov 20 | Nov 24 | Nov 28 | Dec 1 | Dec 5 | Dec 13 |
| 24°F | Nov 16 | Nov 24 | Nov 29 | Dec 3 | Dec 7 | Dec 12 | Dec 17 | Dec 23 | Jan 1 |
| 20°F | Dec 1 | Dec 7 | Dec 14 | Dec 20 | Dec 26 | Jan 1 | Jan 8 | Jan 17 | Jan 29 |
| 16°F | Dec 11 | Dec 18 | Dec 24 | Jan 1 | Jan 5 | Jan 11 | Jan 17 | Jan 27 | 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 | 237 | 228 | 221 | 217 | 211 | 207 | 202 | 197 | 187 |
| 32°F | 262 | 254 | 247 | 242 | 237 | 232 | 227 | 221 | 212 |
| 28°F | 292 | 282 | 275 | 269 | 262 | 257 | 252 | 245 | 235 |
| 24°F | 322 | 312 | 304 | 298 | 292 | 286 | 279 | 271 | 261 |
| 20°F | 361 | 349 | 339 | 333 | 326 | 319 | 310 | 302 | 290 |
| 16°F | 365 | 365 | 365 | 364 | 355 | 346 | 339 | 331 | 316 |
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
- 91% of years
- 16°F or colder
- 64% 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
- 2,763
- Cooling degree days, base 65°F
- 2,236
- Growing degree days, base 40°F
- 8,786
- Growing degree days, base 45°F
- 7,180
- Growing degree days, base 50°F
- 5,705
- Growing degree days, base 55°F
- 4,388
- Growing degree days, base 60°F
- 3,230
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 679 | 0 | 38 |
| February | 507 | 4 | 84 |
| March | 329 | 19 | 213 |
| April | 132 | 56 | 380 |
| May | 31 | 194 | 628 |
| June | 0 | 418 | 868 |
| July | 0 | 544 | 1,009 |
| August | 0 | 553 | 1,018 |
| September | 4 | 334 | 780 |
| October | 118 | 99 | 453 |
| November | 344 | 14 | 181 |
| December | 619 | 2 | 55 |
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 11.5 km from Achille. 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 USC00342680 (Durant 6SSE Mesonet). Public domain.