Lusk Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Lusk 2 Sw. 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 23 and the first fall freeze around September 20, a growing season of about 119 days.
- Median at 36°F
- last June 6, first September 11
- Median at 32°F
- last May 23, first September 20
- Median at 28°F
- last May 10, first October 1
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 17 | Jun 13 | Jun 9 | Jun 6 | Jun 4 | Jun 1 | May 28 | May 23 |
| 32°F | Jun 8 | Jun 3 | May 31 | May 27 | May 23 | May 20 | May 17 | May 14 | May 9 |
| 28°F | May 26 | May 19 | May 16 | May 13 | May 10 | May 7 | May 5 | May 2 | Apr 28 |
| 24°F | May 11 | May 6 | May 3 | May 1 | Apr 29 | Apr 27 | Apr 25 | Apr 22 | Apr 17 |
| 20°F | May 3 | Apr 29 | Apr 26 | Apr 22 | Apr 19 | Apr 17 | Apr 13 | Apr 10 | Apr 5 |
| 16°F | Apr 26 | Apr 20 | Apr 16 | Apr 13 | Apr 9 | Apr 6 | Apr 3 | Mar 31 | Mar 23 |
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 25 | Sep 1 | Sep 5 | Sep 8 | Sep 11 | Sep 13 | Sep 16 | Sep 19 | Sep 23 |
| 32°F | Sep 4 | Sep 10 | Sep 14 | Sep 17 | Sep 20 | Sep 23 | Sep 26 | Sep 29 | Oct 4 |
| 28°F | Sep 17 | Sep 22 | Sep 25 | Sep 28 | Oct 1 | Oct 3 | Oct 6 | Oct 9 | Oct 14 |
| 24°F | Sep 25 | Sep 30 | Oct 4 | Oct 9 | Oct 12 | Oct 15 | Oct 17 | Oct 20 | Oct 24 |
| 20°F | Oct 3 | Oct 10 | Oct 15 | Oct 18 | Oct 22 | Oct 24 | Oct 26 | Oct 29 | Nov 2 |
| 16°F | Oct 12 | Oct 19 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 3 | Nov 6 | Nov 11 |
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 | 116 | 108 | 103 | 99 | 95 | 91 | 86 | 81 | 72 |
| 32°F | 138 | 132 | 128 | 123 | 119 | 115 | 109 | 105 | 97 |
| 28°F | 161 | 154 | 149 | 145 | 141 | 138 | 133 | 128 | 121 |
| 24°F | 182 | 176 | 172 | 168 | 164 | 160 | 155 | 149 | 141 |
| 20°F | 202 | 195 | 190 | 186 | 183 | 179 | 175 | 170 | 161 |
| 16°F | 222 | 214 | 209 | 204 | 200 | 196 | 191 | 186 | 180 |
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
- 7,816
- Cooling degree days, base 65°F
- 348
- Growing degree days, base 40°F
- 3,785
- Growing degree days, base 45°F
- 2,801
- Growing degree days, base 50°F
- 1,976
- Growing degree days, base 55°F
- 1,294
- Growing degree days, base 60°F
- 746
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,273 | 0 | 0 |
| February | 1,113 | 0 | 0 |
| March | 957 | 0 | 6 |
| April | 706 | 0 | 25 |
| May | 433 | 2 | 129 |
| June | 147 | 42 | 354 |
| July | 33 | 155 | 587 |
| August | 41 | 121 | 547 |
| September | 242 | 27 | 269 |
| October | 637 | 0 | 53 |
| November | 970 | 0 | 5 |
| December | 1,264 | 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 2.7 km from Lusk. 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 USC00485830 (Lusk 2 Sw). Public domain.