Greensboro Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Greensboro. 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 18 and the first fall freeze around November 12, a growing season of about 240 days.
- Median at 36°F
- last April 2, first November 1
- Median at 32°F
- last March 18, first November 12
- Median at 28°F
- last March 3, first November 24
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 19 | Apr 14 | Apr 9 | Apr 6 | Apr 2 | Mar 30 | Mar 26 | Mar 20 | Mar 13 |
| 32°F | Apr 6 | Mar 31 | Mar 27 | Mar 23 | Mar 18 | Mar 14 | Mar 10 | Mar 4 | Feb 25 |
| 28°F | Mar 26 | Mar 18 | Mar 13 | Mar 8 | Mar 3 | Feb 27 | Feb 22 | Feb 16 | Feb 5 |
| 24°F | Mar 15 | Mar 6 | Mar 1 | Feb 22 | Feb 14 | Feb 7 | Feb 1 | Jan 27 | Jan 15 |
| 20°F | Mar 7 | Feb 24 | Feb 11 | Feb 2 | Jan 30 | Jan 24 | Jan 19 | Jan 10 | Dec 31 |
| 16°F | Mar 1 | Feb 8 | Feb 1 | Jan 27 | Jan 21 | Jan 16 | Jan 10 | Jan 4 | Dec 28 |
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 21 | Oct 25 | Oct 28 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 17 |
| 32°F | Oct 30 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 19 | Nov 24 | Dec 1 |
| 28°F | Nov 7 | Nov 11 | Nov 16 | Nov 19 | Nov 24 | Nov 29 | Dec 2 | Dec 8 | Dec 21 |
| 24°F | Nov 16 | Nov 24 | Dec 1 | Dec 4 | Dec 11 | Dec 20 | Dec 28 | Jan 3 | Jan 13 |
| 20°F | Dec 3 | Dec 10 | Dec 22 | Dec 30 | Jan 2 | Jan 6 | Jan 12 | Jan 19 | Feb 2 |
| 16°F | Dec 15 | Dec 27 | Jan 1 | Jan 6 | Jan 11 | Jan 16 | Jan 22 | Jan 31 | Feb 12 |
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 | 239 | 230 | 225 | 219 | 215 | 210 | 206 | 200 | 193 |
| 32°F | 267 | 258 | 251 | 246 | 240 | 235 | 229 | 222 | 214 |
| 28°F | 301 | 287 | 280 | 273 | 266 | 260 | 254 | 248 | 237 |
| 24°F | 337 | 325 | 315 | 308 | 301 | 294 | 284 | 276 | 262 |
| 20°F | 365 | 361 | 350 | 342 | 334 | 327 | 318 | 306 | 292 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 355 | 345 | 334 | 324 |
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
- 83% of years
- 16°F or colder
- 50% 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
- 2,368
- Cooling degree days, base 65°F
- 2,052
- Growing degree days, base 40°F
- 8,900
- Growing degree days, base 45°F
- 7,220
- Growing degree days, base 50°F
- 5,676
- Growing degree days, base 55°F
- 4,289
- Growing degree days, base 60°F
- 3,080
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 579 | 1 | 69 |
| February | 418 | 2 | 98 |
| March | 280 | 16 | 236 |
| April | 113 | 60 | 400 |
| May | 19 | 204 | 649 |
| June | 0 | 385 | 835 |
| July | 0 | 484 | 949 |
| August | 0 | 471 | 936 |
| September | 4 | 312 | 757 |
| October | 95 | 100 | 474 |
| November | 334 | 14 | 183 |
| December | 526 | 3 | 89 |
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 2.2 km from Greensboro. 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 USC00013511 (Greensboro). Public domain.