Concow Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Paradise. 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 7 and the first fall freeze around December 18, a growing season of about 313 days.
- Median at 36°F
- last March 31, first November 29
- Median at 32°F
- last February 7, first December 18
- Median at 28°F
- last January 5, first December 31
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 27 | Apr 18 | Apr 12 | Apr 6 | Mar 31 | Mar 23 | Mar 12 | Feb 28 | Feb 17 |
| 32°F | Apr 1 | Mar 10 | Mar 1 | Feb 18 | Feb 7 | Jan 29 | Jan 19 | Jan 8 | Dec 27 |
| 28°F | Feb 14 | Jan 30 | Jan 18 | Jan 11 | Jan 5 | Dec 31 | Dec 27 | Dec 18 | Dec 11 |
| 24°F | – | – | – | – | – | – | – | – | – |
| 20°F | – | – | – | – | – | – | – | – | – |
| 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 11 | Nov 17 | Nov 21 | Nov 25 | Nov 29 | Dec 2 | Dec 6 | Dec 11 | Dec 18 |
| 32°F | Nov 26 | Dec 3 | Dec 8 | Dec 13 | Dec 18 | Dec 25 | Dec 31 | Jan 7 | Jan 27 |
| 28°F | Dec 8 | Dec 13 | Dec 19 | Dec 27 | Dec 31 | Jan 4 | Jan 12 | Jan 20 | Feb 9 |
| 24°F | – | – | – | – | – | – | – | – | – |
| 20°F | – | – | – | – | – | – | – | – | – |
| 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 | 291 | 273 | 260 | 251 | 242 | 234 | 227 | 218 | 206 |
| 32°F | 360 | 346 | 334 | 323 | 313 | 303 | 290 | 275 | 259 |
| 28°F | 365 | 365 | 365 | 365 | 365 | 365 | 362 | 348 | 334 |
| 24°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 |
| 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
- 92% of years
- 28°F or colder
- 35% of years
- 24°F or colder
- 5% of years
- 20°F or colder
- 0% of years
- 16°F or colder
- 0% 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
- 2,842
- Cooling degree days, base 65°F
- 1,574
- Growing degree days, base 40°F
- 7,881
- Growing degree days, base 45°F
- 6,176
- Growing degree days, base 50°F
- 4,682
- Growing degree days, base 55°F
- 3,436
- Growing degree days, base 60°F
- 2,411
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 546 | 0 | 43 |
| February | 444 | 0 | 63 |
| March | 391 | 3 | 135 |
| April | 265 | 19 | 227 |
| May | 120 | 97 | 446 |
| June | 26 | 253 | 677 |
| July | 1 | 439 | 904 |
| August | 1 | 399 | 863 |
| September | 13 | 272 | 709 |
| October | 107 | 87 | 448 |
| November | 363 | 5 | 138 |
| December | 566 | 0 | 29 |
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 8.7 km from Concow. 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 USC00046685 (Paradise). Public domain.