Brusly Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Brusly 2 W. 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 November 24, a growing season of about 268 days.
- Median at 36°F
- last March 17, first November 10
- Median at 32°F
- last February 28, first November 24
- Median at 28°F
- last February 8, first December 9
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 7 | Apr 1 | Mar 27 | Mar 21 | Mar 17 | Mar 12 | Mar 6 | Mar 1 | Feb 22 |
| 32°F | Mar 21 | Mar 14 | Mar 8 | Mar 3 | Feb 28 | Feb 24 | Feb 19 | Feb 10 | Jan 31 |
| 28°F | Mar 8 | Mar 1 | Feb 23 | Feb 16 | Feb 8 | Feb 2 | Jan 29 | Jan 20 | Jan 10 |
| 24°F | Feb 21 | Feb 9 | Feb 2 | Jan 30 | Jan 25 | Jan 18 | Jan 10 | Jan 2 | Dec 22 |
| 20°F | Feb 6 | Jan 31 | Jan 27 | Jan 21 | Jan 14 | Jan 10 | Jan 5 | Dec 31 | Dec 23 |
| 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 | Oct 27 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 14 | Nov 18 | Nov 23 | Nov 28 |
| 32°F | Nov 6 | Nov 11 | Nov 16 | Nov 20 | Nov 24 | Nov 28 | Dec 1 | Dec 6 | Dec 17 |
| 28°F | Nov 17 | Nov 24 | Nov 30 | Dec 4 | Dec 9 | Dec 17 | Dec 25 | Jan 2 | Jan 13 |
| 24°F | Dec 1 | Dec 8 | Dec 16 | Dec 24 | Dec 30 | Jan 4 | Jan 9 | Jan 15 | Feb 1 |
| 20°F | Dec 18 | Dec 26 | Jan 1 | Jan 3 | Jan 7 | Jan 11 | Jan 17 | Jan 26 | Feb 1 |
| 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 | 268 | 258 | 251 | 245 | 240 | 234 | 228 | 220 | 211 |
| 32°F | 305 | 291 | 282 | 274 | 268 | 262 | 256 | 249 | 240 |
| 28°F | 340 | 329 | 320 | 311 | 304 | 296 | 289 | 279 | 267 |
| 24°F | 365 | 365 | 359 | 350 | 343 | 336 | 330 | 321 | 307 |
| 20°F | 365 | 365 | 365 | 365 | 365 | 365 | 363 | 353 | 338 |
| 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
- 73% of years
- 20°F or colder
- 31% of years
- 16°F or colder
- 6% 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
- 1,693
- Cooling degree days, base 65°F
- 2,563
- Growing degree days, base 40°F
- 10,030
- Growing degree days, base 45°F
- 8,285
- Growing degree days, base 50°F
- 6,634
- Growing degree days, base 55°F
- 5,121
- Growing degree days, base 60°F
- 3,755
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 449 | 9 | 134 |
| February | 309 | 17 | 177 |
| March | 171 | 50 | 358 |
| April | 66 | 127 | 513 |
| May | 5 | 295 | 755 |
| June | 0 | 442 | 892 |
| July | 0 | 521 | 986 |
| August | 0 | 515 | 980 |
| September | 2 | 380 | 828 |
| October | 60 | 157 | 565 |
| November | 233 | 35 | 281 |
| December | 398 | 15 | 167 |
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 1.7 km from Brusly. 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 USC00161246 (Brusly 2 W). Public domain.