Stephens Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Magnolia. 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 31 and the first fall freeze around November 2, a growing season of about 218 days.
- Median at 36°F
- last April 10, first October 25
- Median at 32°F
- last March 31, first November 2
- Median at 28°F
- last March 14, first November 13
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 26 | Apr 21 | Apr 18 | Apr 14 | Apr 10 | Apr 7 | Apr 4 | Mar 31 | Mar 25 |
| 32°F | Apr 17 | Apr 10 | Apr 6 | Apr 3 | Mar 31 | Mar 26 | Mar 22 | Mar 16 | Mar 9 |
| 28°F | Apr 4 | Mar 30 | Mar 25 | Mar 19 | Mar 14 | Mar 10 | Mar 5 | Feb 28 | Feb 23 |
| 24°F | Mar 21 | Mar 14 | Mar 10 | Mar 5 | Feb 28 | Feb 25 | Feb 21 | Feb 12 | Jan 31 |
| 20°F | Mar 10 | Mar 3 | Feb 25 | Feb 18 | Feb 11 | Feb 3 | Jan 30 | Jan 23 | Jan 12 |
| 16°F | Mar 1 | Feb 16 | Feb 7 | Jan 31 | Jan 28 | Jan 22 | Jan 15 | Jan 6 | Dec 29 |
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 13 | Oct 17 | Oct 20 | Oct 23 | Oct 25 | Oct 28 | Oct 30 | Nov 2 | Nov 8 |
| 32°F | Oct 21 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 13 | Nov 20 |
| 28°F | Oct 29 | Nov 2 | Nov 5 | Nov 9 | Nov 13 | Nov 17 | Nov 22 | Nov 27 | Dec 3 |
| 24°F | Nov 5 | Nov 12 | Nov 17 | Nov 23 | Nov 27 | Dec 1 | Dec 6 | Dec 11 | Dec 23 |
| 20°F | Nov 16 | Nov 26 | Dec 2 | Dec 7 | Dec 14 | Dec 22 | Dec 31 | Jan 5 | Jan 15 |
| 16°F | Dec 3 | Dec 16 | Dec 25 | Jan 1 | Jan 3 | Jan 7 | Jan 13 | Jan 18 | Feb 1 |
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 | 219 | 211 | 204 | 199 | 196 | 192 | 186 | 181 | 174 |
| 32°F | 244 | 235 | 228 | 223 | 218 | 214 | 209 | 202 | 196 |
| 28°F | 272 | 262 | 255 | 249 | 244 | 238 | 233 | 226 | 215 |
| 24°F | 306 | 295 | 286 | 279 | 273 | 266 | 259 | 252 | 242 |
| 20°F | 346 | 332 | 323 | 314 | 307 | 301 | 292 | 282 | 269 |
| 16°F | 365 | 365 | 359 | 348 | 340 | 334 | 327 | 317 | 304 |
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
- 76% 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
- 2,848
- Cooling degree days, base 65°F
- 2,008
- Growing degree days, base 40°F
- 8,465
- Growing degree days, base 45°F
- 6,875
- Growing degree days, base 50°F
- 5,427
- Growing degree days, base 55°F
- 4,127
- Growing degree days, base 60°F
- 2,985
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 682 | 2 | 48 |
| February | 518 | 3 | 69 |
| March | 342 | 16 | 200 |
| April | 144 | 52 | 366 |
| May | 26 | 188 | 628 |
| June | 0 | 378 | 828 |
| July | 0 | 495 | 959 |
| August | 0 | 484 | 948 |
| September | 10 | 294 | 733 |
| October | 129 | 81 | 424 |
| November | 377 | 13 | 162 |
| December | 620 | 3 | 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 19.9 km from Stephens. 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 USC00034548 (Magnolia). Public domain.