Cave Junction Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Cave Junction 1 Wnw. 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 May 1 and the first fall freeze around October 12, a growing season of about 161 days.
- Median at 36°F
- last May 28, first September 23
- Median at 32°F
- last May 1, first October 12
- Median at 28°F
- last April 4, first November 2
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 | Jun 17 | Jun 11 | Jun 6 | Jun 2 | May 28 | May 23 | May 18 | May 13 | May 5 |
| 32°F | May 23 | May 14 | May 8 | May 4 | May 1 | Apr 29 | Apr 25 | Apr 20 | Apr 14 |
| 28°F | Apr 28 | Apr 21 | Apr 15 | Apr 10 | Apr 4 | Mar 31 | Mar 27 | Mar 17 | Mar 4 |
| 24°F | Mar 31 | Mar 20 | Mar 9 | Feb 28 | Feb 22 | Feb 14 | Feb 1 | Jan 17 | Jan 2 |
| 20°F | Feb 16 | Feb 1 | Jan 22 | Jan 13 | Jan 5 | Dec 31 | Dec 21 | Dec 10 | Nov 27 |
| 16°F | Jan 21 | Jan 13 | Jan 6 | Jan 2 | Dec 29 | Dec 21 | Dec 12 | Dec 3 | Nov 20 |
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 7 | Sep 12 | Sep 16 | Sep 20 | Sep 23 | Sep 27 | Sep 30 | Oct 3 | Oct 9 |
| 32°F | Sep 23 | Sep 30 | Oct 4 | Oct 8 | Oct 12 | Oct 16 | Oct 21 | Oct 26 | Nov 2 |
| 28°F | Oct 12 | Oct 20 | Oct 26 | Oct 31 | Nov 2 | Nov 7 | Nov 15 | Nov 24 | Dec 6 |
| 24°F | Oct 26 | Nov 3 | Nov 12 | Nov 20 | Nov 27 | Dec 4 | Dec 15 | Dec 29 | Jan 12 |
| 20°F | Nov 5 | Nov 17 | Nov 28 | Dec 4 | Dec 14 | Dec 24 | Jan 2 | Jan 10 | Jan 27 |
| 16°F | Nov 13 | Nov 29 | Dec 4 | Dec 13 | Dec 21 | Dec 28 | Jan 2 | Jan 9 | Jan 15 |
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 | 145 | 135 | 129 | 123 | 118 | 113 | 106 | 100 | 92 |
| 32°F | 189 | 181 | 173 | 168 | 161 | 156 | 151 | 142 | 133 |
| 28°F | 251 | 237 | 226 | 218 | 210 | 202 | 195 | 188 | 179 |
| 24°F | 337 | 316 | 305 | 294 | 283 | 270 | 257 | 245 | 230 |
| 20°F | 365 | 365 | 365 | 359 | 350 | 338 | 329 | 315 | 305 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 357 | 341 |
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
- 98% of years
- 20°F or colder
- 65% of years
- 16°F or colder
- 28% 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
- 4,323
- Cooling degree days, base 65°F
- 656
- Growing degree days, base 40°F
- 5,634
- Growing degree days, base 45°F
- 4,158
- Growing degree days, base 50°F
- 2,951
- Growing degree days, base 55°F
- 1,990
- Growing degree days, base 60°F
- 1,232
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 753 | 0 | 4 |
| February | 589 | 0 | 10 |
| March | 549 | 0 | 35 |
| April | 401 | 1 | 102 |
| May | 210 | 21 | 283 |
| June | 80 | 80 | 450 |
| July | 6 | 256 | 715 |
| August | 7 | 212 | 670 |
| September | 61 | 82 | 471 |
| October | 304 | 5 | 186 |
| November | 585 | 0 | 22 |
| December | 777 | 0 | 4 |
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 0.6 km from Cave Junction. 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 USC00351448 (Cave Junction 1 Wnw). Public domain.