Ware Shoals Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Greenwood CO AP. 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 1 and the first fall freeze around November 2, a growing season of about 216 days.
- Median at 36°F
- last April 13, first October 24
- Median at 32°F
- last April 1, first November 2
- Median at 28°F
- last March 19, first November 13
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 27 | Apr 23 | Apr 19 | Apr 17 | Apr 13 | Apr 10 | Apr 6 | Apr 3 | Mar 28 |
| 32°F | Apr 18 | Apr 12 | Apr 7 | Apr 5 | Apr 1 | Mar 29 | Mar 25 | Mar 20 | Mar 14 |
| 28°F | Apr 6 | Mar 31 | Mar 27 | Mar 23 | Mar 19 | Mar 15 | Mar 10 | Mar 3 | Feb 25 |
| 24°F | Mar 26 | Mar 19 | Mar 14 | Mar 7 | Mar 1 | Feb 25 | Feb 19 | Feb 13 | Feb 3 |
| 20°F | Mar 14 | Mar 1 | Feb 24 | Feb 17 | Feb 9 | Feb 3 | Jan 30 | Jan 24 | Jan 13 |
| 16°F | Feb 24 | Feb 13 | Feb 5 | Jan 31 | Jan 26 | Jan 21 | Jan 15 | Jan 7 | Dec 30 |
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 12 | Oct 16 | Oct 19 | Oct 22 | Oct 24 | Oct 27 | Oct 29 | Nov 1 | Nov 5 |
| 32°F | Oct 20 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 11 | Nov 17 |
| 28°F | Oct 31 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 21 | Nov 27 | Dec 3 |
| 24°F | Nov 11 | Nov 17 | Nov 23 | Nov 27 | Dec 1 | Dec 4 | Dec 7 | Dec 16 | Dec 29 |
| 20°F | Nov 26 | Dec 2 | Dec 6 | Dec 12 | Dec 22 | Dec 29 | Jan 3 | Jan 9 | Jan 20 |
| 16°F | Dec 6 | Dec 19 | Dec 26 | Jan 1 | Jan 5 | Jan 10 | Jan 16 | Jan 21 | Jan 31 |
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 | 218 | 209 | 204 | 200 | 196 | 192 | 188 | 182 | 174 |
| 32°F | 241 | 231 | 226 | 220 | 216 | 212 | 208 | 202 | 195 |
| 28°F | 271 | 259 | 253 | 247 | 242 | 237 | 231 | 225 | 217 |
| 24°F | 308 | 296 | 288 | 279 | 273 | 267 | 260 | 253 | 244 |
| 20°F | 346 | 334 | 325 | 316 | 310 | 303 | 295 | 286 | 276 |
| 16°F | 365 | 365 | 356 | 347 | 339 | 333 | 326 | 315 | 303 |
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
- 98% of years
- 16°F or colder
- 80% 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
- 3,048
- Cooling degree days, base 65°F
- 1,676
- Growing degree days, base 40°F
- 7,925
- Growing degree days, base 45°F
- 6,347
- Growing degree days, base 50°F
- 4,933
- Growing degree days, base 55°F
- 3,677
- Growing degree days, base 60°F
- 2,591
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 695 | 0 | 39 |
| February | 532 | 1 | 57 |
| March | 384 | 9 | 163 |
| April | 167 | 43 | 336 |
| May | 40 | 155 | 580 |
| June | 1 | 330 | 778 |
| July | 0 | 445 | 910 |
| August | 0 | 408 | 873 |
| September | 13 | 235 | 672 |
| October | 160 | 45 | 359 |
| November | 424 | 4 | 114 |
| December | 632 | 1 | 52 |
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 18.5 km from Ware Shoals. 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 USW00053874 (Greenwood CO AP). Public domain.