Gardendale Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Odessa Schlemeyer Fld. 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 11, a growing season of about 235 days.
- Median at 36°F
- last April 3, first November 3
- Median at 32°F
- last March 19, first November 11
- Median at 28°F
- last March 7, 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 15 | Apr 10 | Apr 6 | Apr 3 | Mar 31 | Mar 26 | Mar 21 | Mar 14 |
| 32°F | Apr 8 | Apr 2 | Mar 29 | Mar 24 | Mar 19 | Mar 15 | Mar 11 | Mar 7 | Mar 1 |
| 28°F | Mar 27 | Mar 19 | Mar 14 | Mar 11 | Mar 7 | Mar 3 | Feb 28 | Feb 23 | Feb 15 |
| 24°F | Mar 14 | Mar 7 | Mar 2 | Feb 26 | Feb 22 | Feb 16 | Feb 9 | Jan 31 | Jan 23 |
| 20°F | Mar 1 | Feb 20 | Feb 12 | Feb 5 | Jan 31 | Jan 26 | Jan 18 | Jan 7 | Dec 27 |
| 16°F | Feb 14 | Feb 6 | Feb 1 | Jan 27 | Jan 19 | Jan 10 | Jan 2 | Dec 24 | Dec 12 |
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 20 | Oct 25 | Oct 28 | Oct 31 | Nov 3 | Nov 5 | Nov 8 | Nov 10 | Nov 15 |
| 32°F | Oct 29 | Nov 3 | Nov 6 | Nov 9 | Nov 11 | Nov 14 | Nov 17 | Nov 21 | Nov 26 |
| 28°F | Nov 6 | Nov 11 | Nov 15 | Nov 18 | Nov 21 | Nov 24 | Nov 27 | Dec 1 | Dec 6 |
| 24°F | Nov 15 | Nov 21 | Nov 26 | Nov 29 | Dec 3 | Dec 6 | Dec 11 | Dec 16 | Dec 24 |
| 20°F | Nov 27 | Dec 4 | Dec 9 | Dec 15 | Dec 20 | Dec 26 | Jan 1 | Jan 9 | Jan 21 |
| 16°F | Dec 5 | Dec 11 | Dec 20 | Dec 25 | Jan 1 | Jan 9 | Jan 16 | Jan 23 | Feb 4 |
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 | 233 | 227 | 221 | 216 | 212 | 207 | 204 | 198 | 190 |
| 32°F | 259 | 251 | 245 | 240 | 235 | 231 | 226 | 220 | 212 |
| 28°F | 285 | 275 | 269 | 264 | 259 | 253 | 249 | 242 | 233 |
| 24°F | 322 | 307 | 299 | 292 | 285 | 280 | 273 | 266 | 258 |
| 20°F | 361 | 349 | 339 | 331 | 324 | 317 | 309 | 300 | 288 |
| 16°F | 365 | 365 | 365 | 365 | 359 | 351 | 340 | 333 | 323 |
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
- 93% of years
- 16°F or colder
- 54% 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
- 2,512
- Cooling degree days, base 65°F
- 2,478
- Growing degree days, base 40°F
- 9,226
- Growing degree days, base 45°F
- 7,584
- Growing degree days, base 50°F
- 6,077
- Growing degree days, base 55°F
- 4,720
- Growing degree days, base 60°F
- 3,521
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 623 | 0 | 46 |
| February | 443 | 3 | 101 |
| March | 270 | 27 | 260 |
| April | 95 | 105 | 466 |
| May | 18 | 305 | 752 |
| June | 0 | 501 | 951 |
| July | 0 | 570 | 1,035 |
| August | 0 | 539 | 1,004 |
| September | 8 | 307 | 749 |
| October | 95 | 111 | 488 |
| November | 352 | 10 | 176 |
| December | 608 | 0 | 49 |
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 11.1 km from Gardendale. 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 USW00003031 (Odessa Schlemeyer Fld). Public domain.