Pine Island Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Bellville 6NNE. 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 February 28 and the first fall freeze around December 2, a growing season of about 279 days.
- Median at 36°F
- last March 12, first November 19
- Median at 32°F
- last February 28, first December 2
- Median at 28°F
- last February 11, first December 16
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 2 | Mar 27 | Mar 21 | Mar 17 | Mar 12 | Mar 8 | Mar 4 | Feb 28 | Feb 21 |
| 32°F | Mar 20 | Mar 13 | Mar 8 | Mar 3 | Feb 28 | Feb 23 | Feb 18 | Feb 11 | Jan 31 |
| 28°F | Mar 9 | Mar 2 | Feb 24 | Feb 18 | Feb 11 | Feb 4 | Jan 30 | Jan 22 | Jan 10 |
| 24°F | Mar 1 | Feb 14 | Feb 4 | Jan 30 | Jan 25 | Jan 18 | Jan 11 | Jan 2 | Dec 22 |
| 20°F | Feb 10 | Feb 2 | Jan 27 | Jan 21 | Jan 18 | Jan 9 | Jan 4 | Dec 31 | Dec 19 |
| 16°F | – | – | – | – | – | – | – | – | – |
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 | Nov 2 | Nov 8 | Nov 12 | Nov 16 | Nov 19 | Nov 24 | Nov 27 | Dec 1 | Dec 6 |
| 32°F | Nov 12 | Nov 18 | Nov 23 | Nov 28 | Dec 2 | Dec 5 | Dec 10 | Dec 16 | Dec 25 |
| 28°F | Nov 23 | Dec 1 | Dec 5 | Dec 10 | Dec 16 | Dec 24 | Dec 31 | Jan 5 | Jan 15 |
| 24°F | Dec 6 | Dec 13 | Dec 22 | Dec 29 | Jan 1 | Jan 6 | Jan 12 | Jan 19 | Feb 3 |
| 20°F | Dec 14 | Dec 24 | Dec 31 | Jan 1 | Jan 6 | Jan 9 | Jan 17 | Jan 21 | Feb 2 |
| 16°F | – | – | – | – | – | – | – | – | – |
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 | 277 | 269 | 262 | 257 | 253 | 247 | 242 | 236 | 226 |
| 32°F | 309 | 300 | 292 | 285 | 279 | 274 | 267 | 259 | 249 |
| 28°F | 349 | 335 | 327 | 318 | 311 | 304 | 296 | 288 | 278 |
| 24°F | 365 | 365 | 363 | 355 | 347 | 339 | 331 | 320 | 306 |
| 20°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 358 | 340 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 |
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
- 96% of years
- 24°F or colder
- 74% of years
- 20°F or colder
- 31% of years
- 16°F or colder
- 7% 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
- 1,559
- Cooling degree days, base 65°F
- 2,956
- Growing degree days, base 40°F
- 10,564
- Growing degree days, base 45°F
- 8,818
- Growing degree days, base 50°F
- 7,160
- Growing degree days, base 55°F
- 5,613
- Growing degree days, base 60°F
- 4,204
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 448 | 11 | 139 |
| February | 301 | 20 | 197 |
| March | 155 | 65 | 389 |
| April | 47 | 143 | 548 |
| May | 5 | 330 | 790 |
| June | 0 | 493 | 943 |
| July | 0 | 581 | 1,046 |
| August | 0 | 590 | 1,055 |
| September | 0 | 426 | 876 |
| October | 35 | 213 | 644 |
| November | 173 | 67 | 361 |
| December | 396 | 16 | 171 |
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 17.5 km from Pine Island. 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 USC00410655 (Bellville 6NNE). Public domain.