Louise Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Danevang 1 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 15 and the first fall freeze around December 8, a growing season of about 301 days.
- Median at 36°F
- last March 3, first November 27
- Median at 32°F
- last February 15, first December 8
- Median at 28°F
- last January 27, first December 30
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 27 | Mar 18 | Mar 12 | Mar 7 | Mar 3 | Feb 28 | Feb 23 | Feb 18 | Feb 5 |
| 32°F | Mar 13 | Mar 5 | Feb 28 | Feb 22 | Feb 15 | Feb 6 | Jan 31 | Jan 23 | Jan 9 |
| 28°F | Mar 2 | Feb 20 | Feb 12 | Feb 3 | Jan 27 | Jan 20 | Jan 12 | Jan 2 | Dec 21 |
| 24°F | Feb 21 | Feb 5 | Jan 27 | Jan 21 | Jan 15 | Jan 8 | Jan 1 | Dec 26 | Dec 17 |
| 20°F | Feb 13 | Jan 26 | Jan 16 | Jan 10 | Jan 7 | Jan 1 | Dec 31 | Dec 23 | Dec 15 |
| 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 4 | Nov 12 | Nov 17 | Nov 22 | Nov 27 | Dec 1 | Dec 4 | Dec 9 | Dec 21 |
| 32°F | Nov 13 | Nov 24 | Dec 1 | Dec 4 | Dec 8 | Dec 14 | Dec 24 | Jan 1 | Jan 11 |
| 28°F | Dec 1 | Dec 8 | Dec 16 | Dec 24 | Dec 30 | Jan 3 | Jan 9 | Jan 18 | Feb 1 |
| 24°F | Dec 10 | Dec 18 | Dec 26 | Jan 1 | Jan 3 | Jan 8 | Jan 14 | Jan 25 | Feb 7 |
| 20°F | Dec 14 | Dec 22 | Dec 29 | Jan 1 | Jan 3 | Jan 7 | Jan 12 | Jan 21 | 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 | 301 | 289 | 280 | 274 | 267 | 260 | 254 | 246 | 237 |
| 32°F | 341 | 329 | 316 | 307 | 301 | 294 | 285 | 275 | 261 |
| 28°F | 365 | 365 | 354 | 344 | 337 | 329 | 320 | 309 | 300 |
| 24°F | 365 | 365 | 365 | 365 | 365 | 362 | 352 | 342 | 328 |
| 20°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 357 |
| 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
- 98% of years
- 28°F or colder
- 78% of years
- 24°F or colder
- 44% of years
- 20°F or colder
- 14% of years
- 16°F or colder
- 3% 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
- 1,306
- Cooling degree days, base 65°F
- 3,081
- Growing degree days, base 40°F
- 10,922
- Growing degree days, base 45°F
- 9,146
- Growing degree days, base 50°F
- 7,442
- Growing degree days, base 55°F
- 5,845
- Growing degree days, base 60°F
- 4,382
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 385 | 13 | 167 |
| February | 252 | 24 | 227 |
| March | 128 | 77 | 424 |
| April | 34 | 166 | 583 |
| May | 3 | 347 | 809 |
| June | 0 | 492 | 942 |
| July | 0 | 564 | 1,029 |
| August | 0 | 592 | 1,057 |
| September | 1 | 458 | 907 |
| October | 27 | 248 | 687 |
| November | 154 | 76 | 388 |
| December | 323 | 24 | 222 |
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 17.7 km from Louise. 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 USC00412266 (Danevang 1 W). Public domain.