Wyldwood Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Cedar Creek 5 S. 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 14 and the first fall freeze around November 19, a growing season of about 250 days.
- Median at 36°F
- last March 26, first November 6
- Median at 32°F
- last March 14, first November 19
- Median at 28°F
- last March 2, first December 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 | Apr 13 | Apr 6 | Apr 2 | Mar 30 | Mar 26 | Mar 22 | Mar 18 | Mar 13 | Mar 6 |
| 32°F | Apr 3 | Mar 27 | Mar 22 | Mar 18 | Mar 14 | Mar 9 | Mar 5 | Mar 1 | Feb 22 |
| 28°F | Mar 22 | Mar 16 | Mar 11 | Mar 6 | Mar 2 | Feb 27 | Feb 19 | Feb 9 | Jan 29 |
| 24°F | Mar 14 | Mar 6 | Mar 1 | Feb 21 | Feb 10 | Feb 1 | Jan 26 | Jan 19 | Jan 7 |
| 20°F | Mar 7 | Feb 25 | Feb 10 | Jan 30 | Jan 22 | Jan 15 | Jan 9 | Jan 2 | Dec 22 |
| 16°F | Mar 1 | Feb 9 | Jan 24 | Jan 20 | Jan 13 | Jan 8 | Jan 5 | Jan 1 | Dec 19 |
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 23 | Oct 28 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 14 | Nov 19 | Nov 27 |
| 32°F | Oct 31 | Nov 6 | Nov 10 | Nov 15 | Nov 19 | Nov 23 | Nov 28 | Dec 2 | Dec 8 |
| 28°F | Nov 10 | Nov 17 | Nov 22 | Nov 27 | Dec 1 | Dec 5 | Dec 10 | Dec 19 | Dec 31 |
| 24°F | Nov 22 | Dec 1 | Dec 5 | Dec 11 | Dec 21 | Dec 29 | Jan 3 | Jan 10 | Jan 20 |
| 20°F | Dec 4 | Dec 15 | Dec 26 | Jan 1 | Jan 4 | Jan 9 | Jan 17 | Jan 30 | Feb 21 |
| 16°F | Dec 16 | Dec 29 | Jan 1 | Jan 4 | Jan 7 | Jan 15 | Jan 20 | Feb 3 | Feb 28 |
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 | 252 | 243 | 236 | 231 | 226 | 222 | 216 | 210 | 202 |
| 32°F | 279 | 267 | 262 | 255 | 250 | 245 | 239 | 232 | 222 |
| 28°F | 315 | 302 | 292 | 282 | 275 | 268 | 261 | 253 | 245 |
| 24°F | 349 | 337 | 329 | 319 | 309 | 302 | 294 | 285 | 271 |
| 20°F | 365 | 365 | 365 | 365 | 357 | 345 | 335 | 320 | 303 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 350 |
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
- 96% of years
- 20°F or colder
- 64% of years
- 16°F or colder
- 21% 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
- 1,807
- Cooling degree days, base 65°F
- 2,843
- Growing degree days, base 40°F
- 10,207
- Growing degree days, base 45°F
- 8,471
- Growing degree days, base 50°F
- 6,844
- Growing degree days, base 55°F
- 5,351
- Growing degree days, base 60°F
- 4,016
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 486 | 7 | 111 |
| February | 335 | 14 | 164 |
| March | 206 | 44 | 324 |
| April | 71 | 128 | 509 |
| May | 8 | 306 | 763 |
| June | 0 | 492 | 942 |
| July | 0 | 589 | 1,054 |
| August | 0 | 615 | 1,080 |
| September | 1 | 415 | 864 |
| October | 45 | 175 | 596 |
| November | 220 | 44 | 297 |
| December | 435 | 14 | 142 |
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 12.5 km from Wyldwood. 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 USC00411541 (Cedar Creek 5 S). Public domain.