McBain Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Lake City Exp Farm. 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 22 and the first fall freeze around September 26, a growing season of about 125 days.
- Median at 36°F
- last June 4, first September 13
- Median at 32°F
- last May 22, first September 26
- Median at 28°F
- last May 10, first October 8
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 16 | Jun 11 | Jun 7 | Jun 4 | Jun 1 | May 30 | May 26 | May 21 |
| 32°F | Jun 6 | Jun 1 | May 28 | May 25 | May 22 | May 20 | May 16 | May 12 | May 8 |
| 28°F | May 25 | May 21 | May 17 | May 13 | May 10 | May 6 | May 3 | Apr 30 | Apr 25 |
| 24°F | May 15 | May 7 | May 3 | Apr 30 | Apr 27 | Apr 24 | Apr 21 | Apr 17 | Apr 12 |
| 20°F | Apr 30 | Apr 25 | Apr 21 | Apr 18 | Apr 16 | Apr 13 | Apr 10 | Apr 6 | Apr 2 |
| 16°F | Apr 19 | Apr 15 | Apr 12 | Apr 8 | Apr 6 | Apr 3 | Apr 1 | Mar 28 | Mar 22 |
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 9 | Sep 13 | Sep 16 | Sep 19 | Sep 23 | Sep 28 |
| 32°F | Sep 11 | Sep 16 | Sep 20 | Sep 23 | Sep 26 | Sep 29 | Oct 1 | Oct 5 | Oct 9 |
| 28°F | Sep 23 | Sep 28 | Oct 1 | Oct 4 | Oct 8 | Oct 11 | Oct 14 | Oct 19 | Oct 23 |
| 24°F | Oct 3 | Oct 11 | Oct 16 | Oct 19 | Oct 23 | Oct 26 | Oct 28 | Nov 1 | Nov 6 |
| 20°F | Oct 20 | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 14 | Nov 20 |
| 16°F | Nov 1 | Nov 5 | Nov 8 | Nov 11 | Nov 15 | Nov 18 | Nov 22 | Nov 27 | Dec 3 |
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 | 121 | 114 | 109 | 105 | 100 | 96 | 90 | 83 | 71 |
| 32°F | 145 | 138 | 133 | 129 | 125 | 121 | 116 | 111 | 105 |
| 28°F | 172 | 164 | 159 | 154 | 150 | 145 | 141 | 136 | 128 |
| 24°F | 198 | 192 | 187 | 181 | 177 | 172 | 167 | 160 | 152 |
| 20°F | 223 | 216 | 211 | 206 | 203 | 198 | 194 | 188 | 181 |
| 16°F | 244 | 237 | 232 | 228 | 223 | 220 | 216 | 211 | 204 |
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
- 8,086
- Cooling degree days, base 65°F
- 312
- Growing degree days, base 40°F
- 3,755
- Growing degree days, base 45°F
- 2,798
- Growing degree days, base 50°F
- 1,971
- Growing degree days, base 55°F
- 1,270
- Growing degree days, base 60°F
- 706
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,438 | 0 | 0 |
| February | 1,261 | 0 | 0 |
| March | 1,119 | 0 | 6 |
| April | 712 | 1 | 32 |
| May | 368 | 15 | 177 |
| June | 112 | 66 | 406 |
| July | 45 | 121 | 541 |
| August | 63 | 85 | 487 |
| September | 237 | 24 | 258 |
| October | 586 | 2 | 61 |
| November | 906 | 0 | 4 |
| December | 1,238 | 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 12.8 km from McBain. 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 USC00204502 (Lake City Exp Farm). Public domain.