Chauvin Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Galliano. 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 8 and the first fall freeze around December 19, a growing season of about 311 days.
- Median at 36°F
- last February 28, first December 1
- Median at 32°F
- last February 8, first December 19
- Median at 28°F
- last January 28, first January 3
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 | Mar 21 | Mar 14 | Mar 9 | Mar 3 | Feb 28 | Feb 22 | Feb 15 | Feb 6 | Jan 29 |
| 32°F | Mar 12 | Mar 2 | Feb 24 | Feb 16 | Feb 8 | Feb 1 | Jan 29 | Jan 22 | Jan 11 |
| 28°F | Mar 1 | Feb 19 | Feb 9 | Feb 1 | Jan 28 | Jan 22 | Jan 13 | Jan 5 | Dec 27 |
| 24°F | Feb 22 | Feb 8 | Jan 31 | Jan 27 | Jan 20 | Jan 14 | Jan 9 | Jan 1 | Dec 23 |
| 20°F | Feb 12 | Feb 4 | Feb 1 | Jan 28 | Jan 19 | Jan 11 | Jan 9 | Jan 4 | Dec 28 |
| 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 12 | Nov 17 | Nov 22 | Nov 26 | Dec 1 | Dec 4 | Dec 9 | Dec 18 | Dec 29 |
| 32°F | Nov 20 | Nov 30 | Dec 5 | Dec 12 | Dec 19 | Dec 27 | Jan 2 | Jan 9 | Jan 22 |
| 28°F | Dec 3 | Dec 11 | Dec 23 | Dec 31 | Jan 3 | Jan 8 | Jan 15 | Jan 24 | Feb 4 |
| 24°F | Dec 13 | Dec 25 | Jan 1 | Jan 4 | Jan 8 | Jan 14 | Jan 23 | Feb 1 | Feb 10 |
| 20°F | Dec 28 | Jan 2 | Jan 7 | Jan 10 | Jan 18 | Jan 26 | Feb 1 | Feb 1 | Feb 10 |
| 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 | 312 | 300 | 291 | 285 | 279 | 273 | 264 | 257 | 247 |
| 32°F | 350 | 337 | 330 | 320 | 311 | 304 | 296 | 286 | 273 |
| 28°F | 365 | 365 | 363 | 354 | 343 | 335 | 329 | 316 | 302 |
| 24°F | 365 | 365 | 365 | 365 | 365 | 365 | 361 | 346 | 334 |
| 20°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 |
| 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
- 95% of years
- 28°F or colder
- 74% of years
- 24°F or colder
- 38% of years
- 20°F or colder
- 11% of years
- 16°F or colder
- 1% 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
- 1,267
- Cooling degree days, base 65°F
- 2,886
- Growing degree days, base 40°F
- 10,760
- Growing degree days, base 45°F
- 8,978
- Growing degree days, base 50°F
- 7,261
- Growing degree days, base 55°F
- 5,652
- Growing degree days, base 60°F
- 4,187
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 361 | 16 | 189 |
| February | 244 | 27 | 235 |
| March | 135 | 73 | 411 |
| April | 40 | 148 | 559 |
| May | 2 | 329 | 792 |
| June | 0 | 475 | 925 |
| July | 0 | 541 | 1,006 |
| August | 0 | 543 | 1,007 |
| September | 0 | 431 | 880 |
| October | 28 | 220 | 658 |
| November | 157 | 58 | 363 |
| December | 300 | 26 | 235 |
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 28 km from Chauvin. 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 USC00163433 (Galliano). Public domain.