Oxford Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Oxford Ag. 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 30 and the first fall freeze around November 6, a growing season of about 222 days.
- Median at 36°F
- last April 11, first October 28
- Median at 32°F
- last March 30, first November 6
- Median at 28°F
- last March 17, first November 20
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 26 | Apr 21 | Apr 17 | Apr 15 | Apr 11 | Apr 9 | Apr 5 | Apr 2 | Mar 27 |
| 32°F | Apr 14 | Apr 8 | Apr 4 | Apr 1 | Mar 30 | Mar 27 | Mar 24 | Mar 20 | Mar 16 |
| 28°F | Apr 2 | Mar 28 | Mar 24 | Mar 20 | Mar 17 | Mar 14 | Mar 11 | Mar 6 | Feb 28 |
| 24°F | Mar 21 | Mar 15 | Mar 11 | Mar 7 | Mar 3 | Mar 1 | Feb 25 | Feb 20 | Feb 12 |
| 20°F | Mar 9 | Mar 3 | Feb 27 | Feb 21 | Feb 15 | Feb 10 | Feb 4 | Jan 31 | Jan 20 |
| 16°F | Feb 26 | Feb 17 | Feb 8 | Feb 2 | Jan 31 | Jan 27 | Jan 21 | Jan 15 | Jan 7 |
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 15 | Oct 19 | Oct 23 | Oct 25 | Oct 28 | Oct 30 | Nov 1 | Nov 4 | Nov 9 |
| 32°F | Oct 25 | Oct 30 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 13 | Nov 17 | Nov 25 |
| 28°F | Nov 4 | Nov 8 | Nov 12 | Nov 15 | Nov 20 | Nov 24 | Nov 29 | Dec 3 | Dec 10 |
| 24°F | Nov 15 | Nov 22 | Nov 28 | Dec 1 | Dec 6 | Dec 12 | Dec 19 | Dec 27 | Jan 3 |
| 20°F | Dec 1 | Dec 9 | Dec 17 | Dec 25 | Dec 30 | Jan 3 | Jan 9 | Jan 14 | Jan 24 |
| 16°F | Dec 14 | Dec 27 | Jan 1 | Jan 6 | Jan 11 | Jan 15 | Jan 21 | Jan 26 | Feb 1 |
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 | 211 | 207 | 203 | 199 | 196 | 191 | 186 | 177 |
| 32°F | 244 | 236 | 231 | 226 | 222 | 218 | 214 | 210 | 202 |
| 28°F | 278 | 269 | 261 | 256 | 250 | 245 | 240 | 235 | 227 |
| 24°F | 310 | 302 | 295 | 288 | 282 | 276 | 270 | 261 | 252 |
| 20°F | 339 | 330 | 323 | 315 | 308 | 304 | 298 | 292 | 281 |
| 16°F | 365 | 365 | 355 | 346 | 339 | 334 | 327 | 316 | 307 |
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
- 3,574
- Cooling degree days, base 65°F
- 1,551
- Growing degree days, base 40°F
- 7,425
- Growing degree days, base 45°F
- 5,931
- Growing degree days, base 50°F
- 4,592
- Growing degree days, base 55°F
- 3,413
- Growing degree days, base 60°F
- 2,399
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 800 | 0 | 24 |
| February | 640 | 0 | 30 |
| March | 485 | 5 | 112 |
| April | 217 | 38 | 293 |
| May | 60 | 138 | 543 |
| June | 6 | 315 | 759 |
| July | 0 | 442 | 907 |
| August | 0 | 386 | 851 |
| September | 24 | 189 | 615 |
| October | 194 | 36 | 319 |
| November | 456 | 3 | 104 |
| December | 694 | 1 | 36 |
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 1.9 km from Oxford. 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 USC00316510 (Oxford Ag). Public domain.