Acworth Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Dallas 7 Ne. 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 April 2 and the first fall freeze around November 4, a growing season of about 218 days.
- Median at 36°F
- last April 16, first October 26
- Median at 32°F
- last April 2, first November 4
- Median at 28°F
- last March 19, first November 17
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 | May 2 | Apr 27 | Apr 22 | Apr 19 | Apr 16 | Apr 12 | Apr 8 | Apr 4 | Mar 30 |
| 32°F | Apr 19 | Apr 13 | Apr 9 | Apr 5 | Apr 2 | Mar 30 | Mar 25 | Mar 21 | Mar 15 |
| 28°F | Apr 7 | Mar 31 | Mar 28 | Mar 24 | Mar 19 | Mar 15 | Mar 11 | Mar 4 | Feb 25 |
| 24°F | Mar 25 | Mar 19 | Mar 14 | Mar 9 | Mar 3 | Feb 28 | Feb 21 | Feb 15 | Feb 6 |
| 20°F | Mar 13 | Mar 5 | Feb 28 | Feb 19 | Feb 13 | Feb 7 | Feb 2 | Jan 26 | Jan 14 |
| 16°F | Mar 3 | Feb 18 | Feb 8 | Feb 2 | Jan 30 | Jan 24 | Jan 19 | Jan 10 | Jan 1 |
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 14 | Oct 19 | Oct 21 | Oct 24 | Oct 26 | Oct 28 | Oct 31 | Nov 2 | Nov 8 |
| 32°F | Oct 23 | Oct 27 | Oct 31 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 15 | Nov 20 |
| 28°F | Nov 1 | Nov 6 | Nov 10 | Nov 13 | Nov 17 | Nov 20 | Nov 26 | Dec 1 | Dec 7 |
| 24°F | Nov 11 | Nov 19 | Nov 24 | Nov 29 | Dec 2 | Dec 6 | Dec 11 | Dec 19 | Dec 29 |
| 20°F | Nov 26 | Dec 3 | Dec 8 | Dec 14 | Dec 22 | Dec 27 | Jan 1 | Jan 7 | Jan 16 |
| 16°F | Dec 7 | Dec 13 | Dec 24 | Dec 30 | Jan 3 | Jan 7 | Jan 14 | Jan 21 | 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 | 217 | 209 | 203 | 200 | 196 | 191 | 186 | 181 | 175 |
| 32°F | 244 | 234 | 228 | 222 | 218 | 213 | 208 | 202 | 196 |
| 28°F | 273 | 263 | 256 | 249 | 243 | 238 | 232 | 227 | 218 |
| 24°F | 306 | 295 | 286 | 279 | 274 | 267 | 260 | 252 | 242 |
| 20°F | 341 | 330 | 322 | 314 | 306 | 299 | 292 | 283 | 271 |
| 16°F | 365 | 361 | 351 | 342 | 335 | 330 | 323 | 312 | 299 |
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
- 83% 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
- 3,097
- Cooling degree days, base 65°F
- 1,724
- Growing degree days, base 40°F
- 7,973
- Growing degree days, base 45°F
- 6,405
- Growing degree days, base 50°F
- 4,990
- Growing degree days, base 55°F
- 3,734
- Growing degree days, base 60°F
- 2,646
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 718 | 1 | 38 |
| February | 548 | 1 | 52 |
| March | 394 | 11 | 166 |
| April | 176 | 47 | 336 |
| May | 46 | 158 | 577 |
| June | 2 | 331 | 778 |
| July | 0 | 440 | 905 |
| August | 0 | 417 | 882 |
| September | 12 | 251 | 688 |
| October | 147 | 59 | 386 |
| November | 413 | 7 | 130 |
| December | 639 | 2 | 53 |
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 10.1 km from Acworth. 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 USC00092485 (Dallas 7 Ne). Public domain.