Beaver Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Beaver Canyon Pwr House. 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 June 1 and the first fall freeze around September 28, a growing season of about 120 days.
- Median at 36°F
- last June 10, first September 21
- Median at 32°F
- last June 1, first September 28
- Median at 28°F
- last May 19, first October 7
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 23 | Jun 19 | Jun 15 | Jun 12 | Jun 10 | Jun 7 | Jun 4 | Jun 2 | May 29 |
| 32°F | Jun 15 | Jun 9 | Jun 6 | Jun 3 | Jun 1 | May 29 | May 25 | May 21 | May 15 |
| 28°F | Jun 5 | Jun 1 | May 28 | May 23 | May 19 | May 15 | May 12 | May 7 | May 2 |
| 24°F | May 23 | May 16 | May 11 | May 8 | May 4 | May 1 | Apr 28 | Apr 24 | Apr 19 |
| 20°F | May 9 | May 3 | Apr 29 | Apr 26 | Apr 22 | Apr 19 | Apr 16 | Apr 12 | Apr 6 |
| 16°F | Apr 25 | Apr 19 | Apr 15 | Apr 10 | Apr 6 | Apr 3 | Mar 30 | Mar 23 | Mar 15 |
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 4 | Sep 10 | Sep 13 | Sep 18 | Sep 21 | Sep 23 | Sep 25 | Sep 28 | Oct 1 |
| 32°F | Sep 13 | Sep 19 | Sep 23 | Sep 26 | Sep 28 | Oct 1 | Oct 4 | Oct 7 | Oct 11 |
| 28°F | Sep 23 | Sep 28 | Oct 2 | Oct 5 | Oct 7 | Oct 10 | Oct 13 | Oct 17 | Oct 22 |
| 24°F | Oct 1 | Oct 5 | Oct 10 | Oct 13 | Oct 16 | Oct 20 | Oct 23 | Oct 27 | Nov 2 |
| 20°F | Oct 9 | Oct 15 | Oct 19 | Oct 23 | Oct 27 | Oct 31 | Nov 4 | Nov 8 | Nov 14 |
| 16°F | Oct 18 | Oct 25 | Oct 31 | Nov 4 | Nov 7 | Nov 11 | Nov 15 | Nov 19 | Nov 24 |
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 | 119 | 113 | 108 | 104 | 100 | 96 | 92 | 87 | 80 |
| 32°F | 140 | 133 | 129 | 124 | 120 | 115 | 110 | 104 | 97 |
| 28°F | 163 | 155 | 150 | 145 | 141 | 136 | 131 | 126 | 117 |
| 24°F | 185 | 177 | 172 | 168 | 164 | 160 | 155 | 149 | 142 |
| 20°F | 209 | 200 | 195 | 190 | 185 | 181 | 176 | 171 | 163 |
| 16°F | 241 | 231 | 225 | 219 | 214 | 209 | 204 | 197 | 187 |
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
- 100% 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
- 7,627
- Cooling degree days, base 65°F
- 114
- Growing degree days, base 40°F
- 3,352
- Growing degree days, base 45°F
- 2,404
- Growing degree days, base 50°F
- 1,605
- Growing degree days, base 55°F
- 948
- Growing degree days, base 60°F
- 436
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,201 | 0 | 0 |
| February | 1,025 | 0 | 0 |
| March | 933 | 0 | 1 |
| April | 742 | 0 | 7 |
| May | 478 | 1 | 94 |
| June | 173 | 12 | 300 |
| July | 42 | 61 | 484 |
| August | 57 | 37 | 445 |
| September | 236 | 4 | 236 |
| October | 609 | 0 | 38 |
| November | 917 | 0 | 2 |
| December | 1,214 | 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 13.9 km from Beaver. 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 USC00420527 (Beaver Canyon Pwr House). Public domain.