Kake Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Petersburg 1. 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 April 29 and the first fall freeze around October 17, a growing season of about 169 days.
- Median at 36°F
- last May 14, first October 1
- Median at 32°F
- last April 29, first October 17
- Median at 28°F
- last April 11, first November 1
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 | May 29 | May 24 | May 20 | May 17 | May 14 | May 10 | May 6 | May 3 | Apr 30 |
| 32°F | May 14 | May 8 | May 4 | May 2 | Apr 29 | Apr 27 | Apr 24 | Apr 21 | Apr 15 |
| 28°F | Apr 30 | Apr 24 | Apr 18 | Apr 15 | Apr 11 | Apr 8 | Apr 4 | Mar 31 | Mar 26 |
| 24°F | Apr 10 | Apr 4 | Mar 31 | Mar 29 | Mar 25 | Mar 21 | Mar 16 | Mar 10 | Mar 2 |
| 20°F | Mar 27 | Mar 20 | Mar 16 | Mar 11 | Mar 7 | Mar 3 | Feb 28 | Feb 21 | Feb 8 |
| 16°F | Mar 17 | Mar 10 | Mar 4 | Mar 1 | Feb 25 | Feb 19 | Feb 10 | Jan 30 | Jan 14 |
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 | Sep 16 | Sep 21 | Sep 24 | Sep 28 | Oct 1 | Oct 3 | Oct 7 | Oct 11 | Oct 17 |
| 32°F | Sep 30 | Oct 5 | Oct 9 | Oct 13 | Oct 17 | Oct 20 | Oct 23 | Oct 27 | Nov 1 |
| 28°F | Oct 14 | Oct 22 | Oct 26 | Oct 29 | Nov 1 | Nov 4 | Nov 8 | Nov 13 | Nov 20 |
| 24°F | Oct 30 | Nov 5 | Nov 9 | Nov 13 | Nov 17 | Nov 21 | Nov 25 | Dec 1 | Dec 8 |
| 20°F | Nov 9 | Nov 16 | Nov 22 | Nov 27 | Dec 1 | Dec 6 | Dec 12 | Dec 20 | Jan 1 |
| 16°F | Nov 20 | Nov 27 | Dec 3 | Dec 8 | Dec 14 | Dec 21 | Dec 30 | Jan 7 | Jan 21 |
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 | 159 | 152 | 147 | 142 | 138 | 133 | 128 | 123 | 116 |
| 32°F | 189 | 182 | 177 | 173 | 169 | 164 | 159 | 153 | 145 |
| 28°F | 229 | 220 | 213 | 208 | 204 | 198 | 193 | 186 | 177 |
| 24°F | 271 | 259 | 251 | 245 | 240 | 233 | 228 | 222 | 213 |
| 20°F | 305 | 292 | 284 | 277 | 271 | 264 | 257 | 250 | 241 |
| 16°F | 340 | 327 | 314 | 305 | 297 | 290 | 282 | 272 | 262 |
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
- 100% of years
- 16°F or colder
- 98% 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
- 8,018
- Cooling degree days, base 65°F
- 1
- Growing degree days, base 40°F
- 2,284
- Growing degree days, base 45°F
- 1,330
- Growing degree days, base 50°F
- 610
- Growing degree days, base 55°F
- 170
- Growing degree days, base 60°F
- 25
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,057 | 0 | 0 |
| February | 921 | 0 | 0 |
| March | 932 | 0 | 0 |
| April | 707 | 0 | 1 |
| May | 512 | 0 | 38 |
| June | 331 | 1 | 126 |
| July | 268 | 0 | 198 |
| August | 287 | 0 | 180 |
| September | 428 | 0 | 60 |
| October | 673 | 0 | 7 |
| November | 876 | 0 | 0 |
| December | 1,028 | 0 | 0 |
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 64.2 km from Kake. 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 USW00025329 (Petersburg 1). Public domain.