McCloud Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Mccloud. 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 28 and the first fall freeze around September 30, a growing season of about 123 days.
- Median at 36°F
- last June 13, first September 12
- Median at 32°F
- last May 28, first September 30
- Median at 28°F
- last May 3, first October 14
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 27 | Jun 23 | Jun 19 | Jun 16 | Jun 13 | Jun 10 | Jun 7 | Jun 4 | May 30 |
| 32°F | Jun 15 | Jun 8 | Jun 4 | Jun 1 | May 28 | May 22 | May 18 | May 13 | May 7 |
| 28°F | May 28 | May 17 | May 12 | May 7 | May 3 | Apr 30 | Apr 27 | Apr 23 | Apr 18 |
| 24°F | May 6 | Apr 28 | Apr 23 | Apr 19 | Apr 15 | Apr 11 | Apr 7 | Apr 1 | Mar 25 |
| 20°F | Apr 18 | Apr 7 | Apr 1 | Mar 27 | Mar 21 | Mar 16 | Mar 8 | Feb 28 | Feb 18 |
| 16°F | Mar 20 | Mar 8 | Mar 2 | Feb 25 | Feb 18 | Feb 11 | Feb 3 | Jan 23 | Jan 9 |
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 | Aug 27 | Sep 2 | Sep 6 | Sep 9 | Sep 12 | Sep 15 | Sep 18 | Sep 21 | Sep 25 |
| 32°F | Sep 12 | Sep 19 | Sep 24 | Sep 27 | Sep 30 | Oct 1 | Oct 3 | Oct 6 | Oct 11 |
| 28°F | Oct 1 | Oct 5 | Oct 8 | Oct 11 | Oct 14 | Oct 17 | Oct 19 | Oct 23 | Oct 28 |
| 24°F | Oct 15 | Oct 19 | Oct 23 | Oct 27 | Oct 31 | Nov 2 | Nov 5 | Nov 12 | Nov 21 |
| 20°F | Oct 30 | Nov 3 | Nov 8 | Nov 13 | Nov 19 | Nov 24 | Nov 28 | Dec 1 | Dec 8 |
| 16°F | Nov 15 | Nov 23 | Nov 28 | Dec 1 | Dec 5 | Dec 9 | Dec 14 | Dec 20 | Dec 31 |
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 | 108 | 102 | 97 | 93 | 88 | 84 | 80 | 74 | 64 |
| 32°F | 148 | 139 | 134 | 129 | 123 | 118 | 114 | 108 | 99 |
| 28°F | 183 | 176 | 171 | 166 | 162 | 157 | 152 | 145 | 135 |
| 24°F | 228 | 217 | 210 | 203 | 198 | 193 | 186 | 179 | 172 |
| 20°F | 282 | 269 | 261 | 251 | 243 | 236 | 227 | 220 | 207 |
| 16°F | 333 | 320 | 309 | 299 | 291 | 283 | 274 | 265 | 252 |
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
- 99% 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
- 5,612
- Cooling degree days, base 65°F
- 390
- Growing degree days, base 40°F
- 4,466
- Growing degree days, base 45°F
- 3,271
- Growing degree days, base 50°F
- 2,297
- Growing degree days, base 55°F
- 1,504
- Growing degree days, base 60°F
- 863
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 913 | 0 | 0 |
| February | 753 | 0 | 1 |
| March | 739 | 0 | 6 |
| April | 557 | 0 | 47 |
| May | 319 | 12 | 199 |
| June | 132 | 51 | 375 |
| July | 20 | 167 | 612 |
| August | 26 | 118 | 557 |
| September | 122 | 40 | 371 |
| October | 411 | 3 | 121 |
| November | 698 | 0 | 9 |
| December | 924 | 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 0.5 km from McCloud. 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 USC00045449 (Mccloud). Public domain.