Cleone Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Ft Bragg 5 N. 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 2 and the first fall freeze around December 1, a growing season of about 272 days.
- Median at 36°F
- last April 16, first November 6
- Median at 32°F
- last March 2, first December 1
- Median at 28°F
- last January 7, first December 21
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 11 | May 1 | Apr 26 | Apr 21 | Apr 16 | Apr 13 | Apr 9 | Apr 3 | Mar 26 |
| 32°F | Apr 6 | Mar 28 | Mar 18 | Mar 9 | Mar 2 | Feb 24 | Feb 14 | Jan 30 | Jan 8 |
| 28°F | Feb 21 | Feb 5 | Jan 25 | Jan 15 | Jan 7 | Dec 31 | Dec 26 | Dec 18 | Dec 5 |
| 24°F | – | – | – | – | – | – | – | – | – |
| 20°F | – | – | – | – | – | – | – | – | – |
| 16°F | – | – | – | – | – | – | – | – | – |
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 13 | Oct 23 | Oct 30 | Nov 2 | Nov 6 | Nov 10 | Nov 16 | Nov 22 | Nov 30 |
| 32°F | Nov 9 | Nov 17 | Nov 22 | Nov 27 | Dec 1 | Dec 5 | Dec 10 | Dec 22 | Jan 11 |
| 28°F | Nov 22 | Dec 2 | Dec 7 | Dec 11 | Dec 21 | Dec 29 | Jan 4 | Jan 16 | Feb 4 |
| 24°F | – | – | – | – | – | – | – | – | – |
| 20°F | – | – | – | – | – | – | – | – | – |
| 16°F | – | – | – | – | – | – | – | – | – |
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 | 234 | 223 | 215 | 208 | 201 | 195 | 187 | 178 | 160 |
| 32°F | 323 | 305 | 291 | 281 | 272 | 264 | 255 | 245 | 234 |
| 28°F | 365 | 365 | 365 | 365 | 360 | 348 | 339 | 328 | 311 |
| 24°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 |
| 20°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 |
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
- 98% of years
- 28°F or colder
- 55% of years
- 24°F or colder
- 3% of years
- 20°F or colder
- 0% of years
- 16°F or colder
- 0% 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
- 4,908
- Cooling degree days, base 65°F
- 4
- Growing degree days, base 40°F
- 4,236
- Growing degree days, base 45°F
- 2,546
- Growing degree days, base 50°F
- 1,186
- Growing degree days, base 55°F
- 343
- Growing degree days, base 60°F
- 47
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 591 | 0 | 13 |
| February | 500 | 0 | 19 |
| March | 527 | 0 | 25 |
| April | 456 | 0 | 43 |
| May | 385 | 0 | 93 |
| June | 296 | 0 | 156 |
| July | 248 | 0 | 217 |
| August | 235 | 1 | 231 |
| September | 251 | 2 | 202 |
| October | 348 | 1 | 130 |
| November | 473 | 0 | 44 |
| December | 600 | 0 | 13 |
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 3.3 km from Cleone. 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 USC00043161 (Ft Bragg 5 N). Public domain.