Lee County Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Auburn No.2. 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 13 and the first fall freeze around November 17, a growing season of about 246 days.
- Median at 36°F
- last March 29, first November 7
- Median at 32°F
- last March 13, first November 17
- Median at 28°F
- last February 28, first December 1
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 16 | Apr 10 | Apr 5 | Apr 2 | Mar 29 | Mar 25 | Mar 20 | Mar 15 | Mar 8 |
| 32°F | Apr 3 | Mar 27 | Mar 21 | Mar 17 | Mar 13 | Mar 10 | Mar 5 | Feb 28 | Feb 21 |
| 28°F | Mar 19 | Mar 13 | Mar 8 | Mar 4 | Feb 28 | Feb 23 | Feb 18 | Feb 11 | Feb 1 |
| 24°F | Mar 10 | Mar 1 | Feb 24 | Feb 18 | Feb 11 | Feb 5 | Jan 31 | Jan 23 | Jan 10 |
| 20°F | Feb 28 | Feb 17 | Feb 9 | Feb 3 | Jan 30 | Jan 24 | Jan 16 | Jan 7 | Dec 31 |
| 16°F | Feb 13 | Feb 4 | Jan 31 | Jan 25 | Jan 19 | Jan 13 | Jan 8 | Jan 2 | Dec 27 |
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 26 | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 21 |
| 32°F | Nov 1 | Nov 6 | Nov 10 | Nov 13 | Nov 17 | Nov 20 | Nov 24 | Nov 29 | Dec 4 |
| 28°F | Nov 11 | Nov 17 | Nov 23 | Nov 26 | Dec 1 | Dec 4 | Dec 9 | Dec 19 | Dec 29 |
| 24°F | Nov 23 | Dec 1 | Dec 6 | Dec 11 | Dec 19 | Dec 26 | Jan 1 | Jan 7 | Jan 18 |
| 20°F | Dec 10 | Dec 18 | Dec 25 | Jan 1 | Jan 3 | Jan 9 | Jan 16 | Jan 23 | Feb 5 |
| 16°F | Dec 20 | Dec 28 | Jan 1 | Jan 5 | Jan 10 | Jan 16 | Jan 22 | Jan 30 | Feb 7 |
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 | 247 | 239 | 234 | 228 | 223 | 219 | 214 | 208 | 202 |
| 32°F | 275 | 266 | 258 | 252 | 246 | 242 | 238 | 231 | 222 |
| 28°F | 310 | 299 | 290 | 283 | 277 | 270 | 263 | 257 | 248 |
| 24°F | 345 | 334 | 326 | 318 | 310 | 302 | 294 | 285 | 273 |
| 20°F | 365 | 365 | 354 | 344 | 337 | 331 | 324 | 315 | 303 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 363 | 351 | 339 | 331 |
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
- 98% of years
- 20°F or colder
- 80% of years
- 16°F or colder
- 46% 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
- 2,414
- Cooling degree days, base 65°F
- 1,916
- Growing degree days, base 40°F
- 8,718
- Growing degree days, base 45°F
- 7,047
- Growing degree days, base 50°F
- 5,511
- Growing degree days, base 55°F
- 4,134
- Growing degree days, base 60°F
- 2,928
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 599 | 0 | 64 |
| February | 425 | 2 | 95 |
| March | 281 | 13 | 231 |
| April | 110 | 50 | 393 |
| May | 18 | 196 | 643 |
| June | 0 | 365 | 814 |
| July | 0 | 465 | 930 |
| August | 0 | 445 | 910 |
| September | 5 | 290 | 735 |
| October | 100 | 83 | 451 |
| November | 335 | 6 | 166 |
| December | 541 | 1 | 79 |
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 10.2 km from Lee 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 USC00010425 (Auburn No.2). Public domain.