Kirtland Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Fruitland. 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 12 and the first fall freeze around October 4, a growing season of about 143 days.
- Median at 36°F
- last May 27, first September 27
- Median at 32°F
- last May 12, first October 4
- Median at 28°F
- last April 29, first October 15
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 12 | Jun 6 | Jun 2 | May 31 | May 27 | May 23 | May 21 | May 17 | May 11 |
| 32°F | May 29 | May 23 | May 20 | May 16 | May 12 | May 9 | May 5 | May 2 | Apr 29 |
| 28°F | May 12 | May 5 | May 3 | May 1 | Apr 29 | Apr 26 | Apr 23 | Apr 20 | Apr 16 |
| 24°F | Apr 30 | Apr 27 | Apr 23 | Apr 20 | Apr 17 | Apr 13 | Apr 10 | Apr 7 | Apr 2 |
| 20°F | Apr 21 | Apr 15 | Apr 10 | Apr 7 | Apr 3 | Mar 31 | Mar 26 | Mar 19 | Mar 12 |
| 16°F | Apr 11 | Apr 3 | Mar 27 | Mar 19 | Mar 14 | Mar 9 | Mar 6 | Mar 2 | Feb 26 |
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 15 | Sep 19 | Sep 22 | Sep 24 | Sep 27 | Sep 29 | Oct 1 | Oct 5 | Oct 10 |
| 32°F | Sep 21 | Sep 27 | Sep 29 | Oct 2 | Oct 4 | Oct 7 | Oct 11 | Oct 15 | Oct 20 |
| 28°F | Sep 29 | Oct 4 | Oct 8 | Oct 11 | Oct 15 | Oct 18 | Oct 21 | Oct 26 | Nov 1 |
| 24°F | Oct 10 | Oct 15 | Oct 19 | Oct 23 | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 9 |
| 20°F | Oct 19 | Oct 25 | Oct 29 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 13 | Nov 17 |
| 16°F | Oct 30 | Nov 4 | Nov 7 | Nov 10 | Nov 14 | Nov 16 | Nov 18 | Nov 21 | 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 | 140 | 134 | 128 | 124 | 120 | 117 | 113 | 109 | 102 |
| 32°F | 165 | 157 | 152 | 147 | 143 | 139 | 135 | 130 | 123 |
| 28°F | 189 | 181 | 176 | 171 | 167 | 163 | 159 | 153 | 146 |
| 24°F | 211 | 205 | 199 | 195 | 191 | 186 | 181 | 176 | 169 |
| 20°F | 238 | 230 | 224 | 219 | 214 | 209 | 204 | 199 | 190 |
| 16°F | 262 | 256 | 251 | 246 | 241 | 235 | 229 | 222 | 213 |
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
- 5,671
- Cooling degree days, base 65°F
- 750
- Growing degree days, base 40°F
- 5,196
- Growing degree days, base 45°F
- 4,003
- Growing degree days, base 50°F
- 2,963
- Growing degree days, base 55°F
- 2,078
- Growing degree days, base 60°F
- 1,345
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,091 | 0 | 0 |
| February | 854 | 0 | 0 |
| March | 682 | 0 | 12 |
| April | 462 | 0 | 78 |
| May | 199 | 17 | 293 |
| June | 31 | 132 | 550 |
| July | 1 | 297 | 761 |
| August | 3 | 240 | 702 |
| September | 78 | 62 | 436 |
| October | 401 | 1 | 123 |
| November | 781 | 0 | 7 |
| December | 1,088 | 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 1.1 km from Kirtland. 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 USC00293340 (Fruitland). Public domain.