Etowah Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Pisgah Forest 3 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 19 and the first fall freeze around October 23, a growing season of about 186 days.
- Median at 36°F
- last May 2, first October 13
- Median at 32°F
- last April 19, first October 23
- Median at 28°F
- last April 3, 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 15 | May 11 | May 8 | May 5 | May 2 | Apr 30 | Apr 25 | Apr 21 | Apr 16 |
| 32°F | May 8 | May 1 | Apr 26 | Apr 23 | Apr 19 | Apr 16 | Apr 13 | Apr 9 | Apr 2 |
| 28°F | Apr 23 | Apr 16 | Apr 12 | Apr 7 | Apr 3 | Mar 31 | Mar 28 | Mar 23 | Mar 17 |
| 24°F | Apr 6 | Apr 1 | Mar 29 | Mar 25 | Mar 21 | Mar 18 | Mar 14 | Mar 8 | Feb 28 |
| 20°F | Mar 25 | Mar 19 | Mar 15 | Mar 11 | Mar 6 | Mar 1 | Feb 24 | Feb 15 | Feb 7 |
| 16°F | Mar 16 | Mar 8 | Mar 2 | Feb 24 | Feb 15 | Feb 8 | Feb 3 | Jan 30 | Jan 18 |
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 1 | Oct 5 | Oct 8 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 26 |
| 32°F | Oct 9 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Oct 28 | Nov 1 | Nov 4 |
| 28°F | Oct 18 | Oct 23 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 10 | Nov 16 |
| 24°F | Oct 29 | Nov 1 | Nov 5 | Nov 9 | Nov 12 | Nov 16 | Nov 21 | Nov 26 | Dec 1 |
| 20°F | Nov 8 | Nov 14 | Nov 18 | Nov 24 | Nov 28 | Dec 1 | Dec 6 | Dec 12 | Dec 23 |
| 16°F | Nov 21 | Dec 1 | Dec 5 | Dec 10 | Dec 17 | Dec 24 | Dec 31 | Jan 5 | Jan 15 |
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 | 184 | 177 | 172 | 168 | 164 | 160 | 157 | 151 | 143 |
| 32°F | 208 | 201 | 195 | 191 | 186 | 181 | 175 | 170 | 162 |
| 28°F | 234 | 225 | 219 | 215 | 211 | 206 | 201 | 196 | 188 |
| 24°F | 266 | 256 | 249 | 243 | 237 | 232 | 227 | 222 | 214 |
| 20°F | 302 | 289 | 280 | 273 | 267 | 261 | 255 | 248 | 239 |
| 16°F | 339 | 326 | 316 | 307 | 301 | 294 | 287 | 277 | 263 |
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
- 99% 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
- 4,203
- Cooling degree days, base 65°F
- 805
- Growing degree days, base 40°F
- 6,136
- Growing degree days, base 45°F
- 4,711
- Growing degree days, base 50°F
- 3,469
- Growing degree days, base 55°F
- 2,411
- Growing degree days, base 60°F
- 1,523
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 854 | 0 | 11 |
| February | 686 | 0 | 15 |
| March | 564 | 0 | 64 |
| April | 312 | 6 | 183 |
| May | 120 | 48 | 396 |
| June | 17 | 158 | 591 |
| July | 1 | 254 | 718 |
| August | 2 | 224 | 687 |
| September | 50 | 101 | 501 |
| October | 271 | 14 | 234 |
| November | 556 | 1 | 53 |
| December | 769 | 0 | 18 |
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 7.1 km from Etowah. 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 USC00316805 (Pisgah Forest 3 Ne). Public domain.