Forest Oaks Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Greensboro Wtp. 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 1 and the first fall freeze around November 4, a growing season of about 217 days.
- Median at 36°F
- last April 12, first October 27
- Median at 32°F
- last April 1, first November 4
- Median at 28°F
- last March 22, first November 15
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 27 | Apr 21 | Apr 17 | Apr 15 | Apr 12 | Apr 9 | Apr 6 | Apr 3 | Mar 30 |
| 32°F | Apr 14 | Apr 9 | Apr 5 | Apr 3 | Apr 1 | Mar 29 | Mar 26 | Mar 23 | Mar 18 |
| 28°F | Apr 5 | Mar 31 | Mar 28 | Mar 25 | Mar 22 | Mar 19 | Mar 15 | Mar 10 | Mar 3 |
| 24°F | Mar 25 | Mar 20 | Mar 17 | Mar 12 | Mar 8 | Mar 3 | Feb 28 | Feb 25 | Feb 17 |
| 20°F | Mar 17 | Mar 10 | Mar 4 | Mar 1 | Feb 26 | Feb 21 | Feb 12 | Feb 5 | Jan 28 |
| 16°F | Mar 7 | Feb 28 | Feb 22 | Feb 13 | Feb 5 | Jan 31 | Jan 26 | Jan 18 | Jan 6 |
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 18 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 8 |
| 32°F | Oct 23 | Oct 28 | Oct 31 | Nov 2 | Nov 4 | Nov 6 | Nov 9 | Nov 13 | Nov 19 |
| 28°F | Nov 1 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 19 | Nov 23 | Nov 27 | Dec 2 |
| 24°F | Nov 12 | Nov 17 | Nov 21 | Nov 26 | Nov 30 | Dec 2 | Dec 7 | Dec 13 | Dec 24 |
| 20°F | Nov 23 | Dec 1 | Dec 6 | Dec 10 | Dec 16 | Dec 24 | Dec 30 | Jan 5 | Jan 12 |
| 16°F | Dec 9 | Dec 19 | Dec 27 | Jan 1 | Jan 5 | Jan 11 | Jan 16 | Jan 23 | Jan 31 |
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 | 215 | 208 | 203 | 200 | 197 | 193 | 189 | 184 | 178 |
| 32°F | 239 | 231 | 226 | 222 | 217 | 214 | 210 | 205 | 197 |
| 28°F | 266 | 256 | 251 | 246 | 242 | 236 | 231 | 226 | 219 |
| 24°F | 296 | 286 | 279 | 272 | 267 | 263 | 257 | 251 | 244 |
| 20°F | 331 | 319 | 309 | 304 | 297 | 291 | 285 | 277 | 267 |
| 16°F | 365 | 351 | 342 | 333 | 326 | 318 | 310 | 303 | 293 |
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
- 100% of years
- 16°F or colder
- 92% 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
- 3,438
- Cooling degree days, base 65°F
- 1,567
- Growing degree days, base 40°F
- 7,526
- Growing degree days, base 45°F
- 6,004
- Growing degree days, base 50°F
- 4,649
- Growing degree days, base 55°F
- 3,459
- Growing degree days, base 60°F
- 2,431
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 778 | 0 | 20 |
| February | 604 | 1 | 42 |
| March | 451 | 5 | 127 |
| April | 190 | 34 | 308 |
| May | 50 | 151 | 566 |
| June | 3 | 304 | 752 |
| July | 0 | 451 | 916 |
| August | 1 | 383 | 848 |
| September | 20 | 197 | 627 |
| October | 187 | 39 | 328 |
| November | 462 | 2 | 86 |
| December | 693 | 1 | 30 |
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 13.8 km from Forest Oaks. 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 USC00313625 (Greensboro Wtp). Public domain.