Pray Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Livingston 12 S. 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 19 and the first fall freeze around September 25, a growing season of about 125 days.
- Median at 36°F
- last June 8, first September 11
- Median at 32°F
- last May 19, first September 25
- Median at 28°F
- last May 4, first October 5
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 30 | Jun 22 | Jun 15 | Jun 11 | Jun 8 | Jun 4 | May 31 | May 27 | May 21 |
| 32°F | Jun 11 | Jun 2 | May 27 | May 23 | May 19 | May 16 | May 12 | May 9 | May 5 |
| 28°F | May 19 | May 14 | May 10 | May 7 | May 4 | May 1 | Apr 29 | Apr 24 | Apr 18 |
| 24°F | May 7 | May 2 | Apr 29 | Apr 24 | Apr 20 | Apr 17 | Apr 13 | Apr 9 | Apr 3 |
| 20°F | Apr 28 | Apr 20 | Apr 14 | Apr 11 | Apr 7 | Apr 3 | Mar 31 | Mar 27 | Mar 20 |
| 16°F | Apr 14 | Apr 7 | Apr 3 | Mar 30 | Mar 26 | Mar 22 | Mar 17 | Mar 11 | Mar 5 |
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 26 | Sep 1 | Sep 4 | Sep 8 | Sep 11 | Sep 15 | Sep 18 | Sep 22 | Sep 28 |
| 32°F | Sep 7 | Sep 13 | Sep 19 | Sep 22 | Sep 25 | Sep 28 | Oct 1 | Oct 3 | Oct 7 |
| 28°F | Sep 21 | Sep 26 | Sep 30 | Oct 2 | Oct 5 | Oct 7 | Oct 11 | Oct 15 | Oct 21 |
| 24°F | Sep 30 | Oct 4 | Oct 8 | Oct 11 | Oct 16 | Oct 19 | Oct 24 | Oct 28 | Nov 2 |
| 20°F | Oct 7 | Oct 14 | Oct 19 | Oct 23 | Oct 28 | Nov 1 | Nov 3 | Nov 8 | Nov 13 |
| 16°F | Oct 18 | Oct 23 | Oct 29 | Nov 1 | Nov 4 | Nov 8 | Nov 12 | Nov 16 | Nov 23 |
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 | 118 | 110 | 104 | 99 | 93 | 88 | 83 | 77 | 66 |
| 32°F | 146 | 139 | 135 | 130 | 125 | 120 | 115 | 107 | 99 |
| 28°F | 175 | 167 | 161 | 157 | 152 | 148 | 144 | 139 | 132 |
| 24°F | 201 | 193 | 187 | 182 | 176 | 171 | 166 | 161 | 153 |
| 20°F | 228 | 219 | 212 | 207 | 201 | 195 | 190 | 182 | 173 |
| 16°F | 252 | 242 | 235 | 228 | 223 | 218 | 212 | 206 | 196 |
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
- 7,278
- Cooling degree days, base 65°F
- 239
- Growing degree days, base 40°F
- 3,724
- Growing degree days, base 45°F
- 2,668
- Growing degree days, base 50°F
- 1,799
- Growing degree days, base 55°F
- 1,109
- Growing degree days, base 60°F
- 588
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,159 | 0 | 0 |
| February | 1,007 | 0 | 1 |
| March | 865 | 0 | 8 |
| April | 633 | 0 | 28 |
| May | 409 | 3 | 125 |
| June | 192 | 18 | 284 |
| July | 44 | 112 | 533 |
| August | 60 | 86 | 493 |
| September | 242 | 20 | 253 |
| October | 590 | 1 | 65 |
| November | 899 | 0 | 10 |
| December | 1,179 | 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 16 km from Pray. 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 USC00245080 (Livingston 12 S). Public domain.