Edgeworth Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Glenwillard Dashields L&d. 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 8 and the first fall freeze around November 8, a growing season of about 212 days.
- Median at 36°F
- last April 24, first October 28
- Median at 32°F
- last April 8, first November 8
- Median at 28°F
- last March 29, first November 18
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 13 | May 7 | May 2 | Apr 28 | Apr 24 | Apr 21 | Apr 17 | Apr 13 | Apr 7 |
| 32°F | Apr 26 | Apr 20 | Apr 16 | Apr 12 | Apr 8 | Apr 5 | Apr 2 | Mar 30 | Mar 25 |
| 28°F | Apr 12 | Apr 6 | Apr 3 | Mar 31 | Mar 29 | Mar 27 | Mar 23 | Mar 19 | Mar 14 |
| 24°F | Mar 31 | Mar 28 | Mar 25 | Mar 22 | Mar 19 | Mar 16 | Mar 13 | Mar 8 | Mar 2 |
| 20°F | Mar 25 | Mar 20 | Mar 16 | Mar 12 | Mar 9 | Mar 5 | Mar 1 | Feb 25 | Feb 16 |
| 16°F | Mar 17 | Mar 12 | Mar 8 | Mar 4 | Feb 28 | Feb 24 | Feb 19 | Feb 11 | Feb 2 |
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 18 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 10 |
| 32°F | Oct 27 | Nov 1 | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 18 | Nov 24 |
| 28°F | Nov 5 | Nov 9 | Nov 12 | Nov 15 | Nov 18 | Nov 22 | Nov 25 | Nov 29 | Dec 4 |
| 24°F | Nov 12 | Nov 18 | Nov 22 | Nov 26 | Nov 30 | Dec 2 | Dec 6 | Dec 12 | Dec 19 |
| 20°F | Nov 21 | Nov 28 | Dec 2 | Dec 6 | Dec 10 | Dec 15 | Dec 20 | Dec 26 | Jan 2 |
| 16°F | Dec 1 | Dec 10 | Dec 15 | Dec 21 | Dec 26 | Dec 30 | Jan 3 | Jan 10 | Jan 17 |
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 | 209 | 201 | 195 | 190 | 186 | 181 | 176 | 171 | 163 |
| 32°F | 233 | 226 | 222 | 217 | 212 | 208 | 204 | 199 | 190 |
| 28°F | 256 | 248 | 243 | 239 | 235 | 229 | 226 | 221 | 215 |
| 24°F | 281 | 272 | 266 | 260 | 254 | 250 | 244 | 239 | 232 |
| 20°F | 304 | 295 | 287 | 283 | 277 | 272 | 266 | 260 | 252 |
| 16°F | 327 | 316 | 308 | 304 | 298 | 293 | 287 | 280 | 272 |
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
- 5,644
- Cooling degree days, base 65°F
- 840
- Growing degree days, base 40°F
- 5,466
- Growing degree days, base 45°F
- 4,270
- Growing degree days, base 50°F
- 3,218
- Growing degree days, base 55°F
- 2,294
- Growing degree days, base 60°F
- 1,499
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,142 | 0 | 1 |
| February | 956 | 0 | 2 |
| March | 836 | 1 | 25 |
| April | 438 | 2 | 119 |
| May | 167 | 49 | 360 |
| June | 21 | 162 | 591 |
| July | 1 | 277 | 741 |
| August | 4 | 241 | 702 |
| September | 73 | 97 | 475 |
| October | 348 | 12 | 180 |
| November | 687 | 0 | 22 |
| December | 972 | 0 | 3 |
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 1.1 km from Edgeworth. 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 USC00363343 (Glenwillard Dashields L&d). Public domain.