Sturgis Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Ft Meade. 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 8 and the first fall freeze around October 3, a growing season of about 147 days.
- Median at 36°F
- last May 19, first September 24
- Median at 32°F
- last May 8, first October 3
- Median at 28°F
- last April 28, first October 13
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 31 | May 27 | May 24 | May 21 | May 19 | May 16 | May 14 | May 10 | May 6 |
| 32°F | May 21 | May 17 | May 14 | May 11 | May 8 | May 5 | May 2 | Apr 30 | Apr 26 |
| 28°F | May 11 | May 6 | May 3 | Apr 30 | Apr 28 | Apr 25 | Apr 21 | Apr 18 | Apr 13 |
| 24°F | May 1 | Apr 27 | Apr 23 | Apr 20 | Apr 17 | Apr 13 | Apr 10 | Apr 7 | Apr 2 |
| 20°F | Apr 21 | Apr 17 | Apr 12 | Apr 9 | Apr 6 | Apr 4 | Apr 1 | Mar 28 | Mar 21 |
| 16°F | Apr 14 | Apr 8 | Apr 5 | Apr 2 | Mar 30 | Mar 26 | Mar 21 | Mar 15 | Mar 8 |
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 11 | Sep 16 | Sep 19 | Sep 22 | Sep 24 | Sep 27 | Sep 29 | Oct 2 | Oct 6 |
| 32°F | Sep 19 | Sep 23 | Sep 28 | Oct 1 | Oct 3 | Oct 5 | Oct 8 | Oct 12 | Oct 17 |
| 28°F | Sep 27 | Oct 2 | Oct 5 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 23 | Oct 27 |
| 24°F | Oct 6 | Oct 11 | Oct 17 | Oct 20 | Oct 23 | Oct 25 | Oct 29 | Nov 1 | Nov 5 |
| 20°F | Oct 17 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 6 | Nov 9 | Nov 15 |
| 16°F | Oct 24 | Oct 28 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 19 | 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 | 145 | 139 | 135 | 131 | 127 | 124 | 121 | 116 | 109 |
| 32°F | 166 | 160 | 154 | 151 | 147 | 143 | 139 | 134 | 128 |
| 28°F | 188 | 181 | 176 | 171 | 167 | 162 | 158 | 153 | 147 |
| 24°F | 207 | 201 | 196 | 191 | 187 | 184 | 180 | 175 | 166 |
| 20°F | 227 | 219 | 214 | 209 | 205 | 200 | 196 | 191 | 184 |
| 16°F | 246 | 238 | 231 | 226 | 221 | 217 | 212 | 207 | 199 |
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
- 6,780
- Cooling degree days, base 65°F
- 691
- Growing degree days, base 40°F
- 4,744
- Growing degree days, base 45°F
- 3,634
- Growing degree days, base 50°F
- 2,685
- Growing degree days, base 55°F
- 1,882
- Growing degree days, base 60°F
- 1,216
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,197 | 0 | 1 |
| February | 1,040 | 0 | 3 |
| March | 879 | 0 | 18 |
| April | 582 | 2 | 64 |
| May | 317 | 18 | 213 |
| June | 77 | 98 | 473 |
| July | 10 | 262 | 717 |
| August | 19 | 228 | 675 |
| September | 145 | 79 | 397 |
| October | 515 | 5 | 108 |
| November | 858 | 0 | 15 |
| December | 1,142 | 0 | 1 |
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 2.6 km from Sturgis. 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 USC00393069 (Ft Meade). Public domain.