Clayton Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Woodstown Pittsgrov 4E. 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 11 and the first fall freeze around November 3, a growing season of about 206 days.
- Median at 36°F
- last April 26, first October 23
- Median at 32°F
- last April 11, first November 3
- Median at 28°F
- last March 30, first November 14
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 5 | May 1 | Apr 29 | Apr 26 | Apr 22 | Apr 19 | Apr 16 | Apr 11 |
| 32°F | Apr 27 | Apr 21 | Apr 18 | Apr 15 | Apr 11 | Apr 8 | Apr 5 | Apr 2 | Mar 29 |
| 28°F | Apr 14 | Apr 8 | Apr 4 | Apr 1 | Mar 30 | Mar 26 | Mar 22 | Mar 18 | Mar 12 |
| 24°F | Mar 31 | Mar 27 | Mar 22 | Mar 19 | Mar 16 | Mar 12 | Mar 9 | Mar 4 | Feb 27 |
| 20°F | Mar 20 | Mar 14 | Mar 10 | Mar 7 | Mar 4 | Mar 1 | Feb 25 | Feb 19 | Feb 11 |
| 16°F | Mar 9 | Mar 5 | Feb 28 | Feb 24 | Feb 19 | Feb 14 | Feb 7 | Feb 3 | Jan 24 |
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 7 | Oct 12 | Oct 16 | Oct 20 | Oct 23 | Oct 26 | Oct 30 | Nov 2 | Nov 7 |
| 32°F | Oct 18 | Oct 24 | Oct 28 | Oct 31 | Nov 3 | Nov 5 | Nov 9 | Nov 13 | Nov 18 |
| 28°F | Oct 31 | Nov 4 | Nov 8 | Nov 11 | Nov 14 | Nov 17 | Nov 22 | Nov 27 | Dec 2 |
| 24°F | Nov 10 | Nov 16 | Nov 21 | Nov 25 | Nov 29 | Dec 2 | Dec 5 | Dec 10 | Dec 17 |
| 20°F | Nov 24 | Dec 1 | Dec 5 | Dec 10 | Dec 14 | Dec 20 | Dec 24 | Dec 30 | Jan 6 |
| 16°F | Dec 9 | Dec 16 | Dec 21 | Dec 26 | Dec 30 | Jan 2 | Jan 8 | Jan 14 | Jan 24 |
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 | 200 | 194 | 189 | 185 | 180 | 176 | 172 | 166 | 158 |
| 32°F | 227 | 220 | 215 | 210 | 206 | 201 | 197 | 191 | 184 |
| 28°F | 257 | 248 | 241 | 236 | 231 | 227 | 222 | 216 | 208 |
| 24°F | 284 | 275 | 268 | 262 | 257 | 252 | 248 | 242 | 233 |
| 20°F | 309 | 301 | 295 | 290 | 285 | 280 | 275 | 268 | 259 |
| 16°F | 337 | 328 | 322 | 315 | 310 | 305 | 300 | 294 | 287 |
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
- 4,510
- Cooling degree days, base 65°F
- 1,207
- Growing degree days, base 40°F
- 6,408
- Growing degree days, base 45°F
- 5,054
- Growing degree days, base 50°F
- 3,859
- Growing degree days, base 55°F
- 2,823
- Growing degree days, base 60°F
- 1,939
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 950 | 0 | 9 |
| February | 801 | 0 | 6 |
| March | 650 | 1 | 39 |
| April | 335 | 12 | 173 |
| May | 122 | 73 | 417 |
| June | 14 | 239 | 675 |
| July | 0 | 386 | 851 |
| August | 1 | 315 | 780 |
| September | 36 | 154 | 569 |
| October | 249 | 25 | 259 |
| November | 543 | 2 | 69 |
| December | 809 | 0 | 15 |
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 14.1 km from Clayton. 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 USC00289910 (Woodstown Pittsgrov 4E). Public domain.