Fairview Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Swannanoa 2 Sse. 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 22 and the first fall freeze around October 24, a growing season of about 184 days.
- Median at 36°F
- last May 5, first October 14
- Median at 32°F
- last April 22, first October 24
- Median at 28°F
- last April 9, first November 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 | May 21 | May 15 | May 11 | May 8 | May 5 | May 1 | Apr 28 | Apr 23 | Apr 17 |
| 32°F | May 11 | May 4 | Apr 30 | Apr 25 | Apr 22 | Apr 18 | Apr 15 | Apr 10 | Apr 5 |
| 28°F | Apr 27 | Apr 21 | Apr 17 | Apr 13 | Apr 9 | Apr 5 | Apr 2 | Mar 29 | Mar 23 |
| 24°F | Apr 15 | Apr 9 | Apr 5 | Apr 2 | Mar 31 | Mar 27 | Mar 23 | Mar 18 | Mar 11 |
| 20°F | Apr 6 | Apr 1 | Mar 28 | Mar 25 | Mar 21 | Mar 17 | Mar 13 | Mar 8 | Mar 1 |
| 16°F | Mar 30 | Mar 24 | Mar 19 | Mar 15 | Mar 10 | Mar 6 | Mar 1 | Feb 23 | Feb 13 |
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 | Sep 29 | Oct 5 | Oct 9 | Oct 12 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 27 |
| 32°F | Oct 11 | Oct 15 | Oct 19 | Oct 22 | Oct 24 | Oct 27 | Oct 29 | Nov 1 | Nov 6 |
| 28°F | Oct 19 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 11 | Nov 16 |
| 24°F | Oct 27 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 14 | Nov 18 | Nov 24 | Dec 1 |
| 20°F | Nov 5 | Nov 10 | Nov 15 | Nov 18 | Nov 23 | Nov 28 | Dec 1 | Dec 6 | Dec 13 |
| 16°F | Nov 14 | Nov 22 | Nov 28 | Dec 1 | Dec 5 | Dec 9 | Dec 15 | Dec 23 | Jan 2 |
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 | 182 | 175 | 170 | 166 | 161 | 158 | 154 | 149 | 142 |
| 32°F | 205 | 197 | 192 | 187 | 184 | 179 | 175 | 169 | 162 |
| 28°F | 227 | 220 | 214 | 209 | 205 | 200 | 196 | 190 | 182 |
| 24°F | 249 | 242 | 235 | 230 | 224 | 220 | 215 | 209 | 202 |
| 20°F | 273 | 265 | 259 | 253 | 248 | 243 | 238 | 231 | 222 |
| 16°F | 303 | 292 | 283 | 276 | 271 | 265 | 259 | 252 | 242 |
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
- 100% 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
- 5,274
- Cooling degree days, base 65°F
- 325
- Growing degree days, base 40°F
- 5,037
- Growing degree days, base 45°F
- 3,746
- Growing degree days, base 50°F
- 2,621
- Growing degree days, base 55°F
- 1,663
- Growing degree days, base 60°F
- 882
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,000 | 0 | 3 |
| February | 826 | 0 | 6 |
| March | 699 | 0 | 42 |
| April | 404 | 5 | 147 |
| May | 191 | 22 | 308 |
| June | 60 | 61 | 452 |
| July | 11 | 117 | 570 |
| August | 27 | 89 | 527 |
| September | 121 | 29 | 361 |
| October | 377 | 2 | 156 |
| November | 663 | 0 | 40 |
| December | 896 | 0 | 10 |
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 6.7 km from Fairview. 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 USC00318448 (Swannanoa 2 Sse). Public domain.