Stearns Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Stearns 2S. 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 April 24 and the first fall freeze around October 18, a growing season of about 177 days.
- Median at 36°F
- last May 4, first October 9
- Median at 32°F
- last April 24, first October 18
- Median at 28°F
- last April 10, first October 29
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 | May 21 | May 14 | May 10 | May 6 | May 4 | Apr 30 | Apr 28 | Apr 25 | Apr 20 |
| 32°F | May 11 | May 5 | May 1 | Apr 27 | Apr 24 | Apr 20 | Apr 17 | Apr 14 | Apr 8 |
| 28°F | Apr 30 | Apr 23 | Apr 18 | Apr 13 | Apr 10 | Apr 7 | Apr 4 | Mar 31 | Mar 24 |
| 24°F | Apr 12 | Apr 6 | Apr 4 | Apr 1 | Mar 29 | Mar 25 | Mar 20 | Mar 15 | Mar 7 |
| 20°F | Apr 2 | Mar 27 | Mar 22 | Mar 18 | Mar 14 | Mar 10 | Mar 5 | Feb 28 | Feb 22 |
| 16°F | Mar 23 | Mar 16 | Mar 10 | Mar 6 | Mar 1 | Feb 26 | Feb 21 | Feb 14 | Feb 7 |
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 27 | Oct 1 | Oct 4 | Oct 7 | Oct 9 | Oct 12 | Oct 15 | Oct 18 | Oct 23 |
| 32°F | Oct 4 | Oct 8 | Oct 13 | Oct 15 | Oct 18 | Oct 21 | Oct 24 | Oct 29 | Nov 2 |
| 28°F | Oct 13 | Oct 19 | Oct 22 | Oct 25 | Oct 29 | Nov 1 | Nov 2 | Nov 6 | Nov 11 |
| 24°F | Oct 23 | Oct 28 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 14 | Nov 19 | Nov 25 |
| 20°F | Nov 3 | Nov 7 | Nov 12 | Nov 16 | Nov 20 | Nov 24 | Nov 30 | Dec 3 | Dec 11 |
| 16°F | Nov 13 | Nov 21 | Nov 26 | Dec 1 | Dec 5 | Dec 11 | Dec 17 | Dec 23 | Dec 30 |
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 | 178 | 172 | 166 | 162 | 158 | 155 | 150 | 145 | 138 |
| 32°F | 198 | 191 | 186 | 181 | 177 | 172 | 167 | 162 | 154 |
| 28°F | 221 | 214 | 210 | 204 | 200 | 195 | 190 | 185 | 176 |
| 24°F | 251 | 241 | 234 | 229 | 224 | 219 | 215 | 210 | 201 |
| 20°F | 279 | 270 | 263 | 257 | 251 | 246 | 240 | 232 | 224 |
| 16°F | 311 | 301 | 293 | 285 | 278 | 272 | 267 | 260 | 250 |
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
- 4,615
- Cooling degree days, base 65°F
- 948
- Growing degree days, base 40°F
- 6,133
- Growing degree days, base 45°F
- 4,779
- Growing degree days, base 50°F
- 3,583
- Growing degree days, base 55°F
- 2,546
- Growing degree days, base 60°F
- 1,669
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 947 | 0 | 10 |
| February | 783 | 0 | 14 |
| March | 599 | 0 | 66 |
| April | 322 | 14 | 196 |
| May | 115 | 70 | 423 |
| June | 21 | 188 | 616 |
| July | 1 | 291 | 755 |
| August | 4 | 255 | 716 |
| September | 56 | 115 | 509 |
| October | 312 | 14 | 211 |
| November | 607 | 1 | 51 |
| December | 849 | 0 | 17 |
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 2.8 km from Stearns. 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 USC00157677 (Stearns 2S). Public domain.