Evart Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Big Rapids Wtp. 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 13 and the first fall freeze around October 2, a growing season of about 142 days.
- Median at 36°F
- last May 25, first September 22
- Median at 32°F
- last May 13, first October 2
- Median at 28°F
- last April 30, 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 | Jun 10 | Jun 3 | May 31 | May 28 | May 25 | May 22 | May 19 | May 16 | May 9 |
| 32°F | May 28 | May 23 | May 20 | May 17 | May 13 | May 9 | May 5 | May 2 | Apr 28 |
| 28°F | May 17 | May 12 | May 6 | May 3 | Apr 30 | Apr 29 | Apr 26 | Apr 22 | Apr 18 |
| 24°F | May 4 | Apr 30 | Apr 26 | Apr 22 | Apr 19 | Apr 17 | Apr 13 | Apr 10 | Apr 6 |
| 20°F | Apr 22 | Apr 17 | Apr 13 | Apr 10 | Apr 8 | Apr 5 | Apr 3 | Mar 31 | Mar 24 |
| 16°F | Apr 12 | Apr 7 | Apr 4 | Apr 2 | Mar 31 | Mar 28 | Mar 24 | Mar 20 | Mar 16 |
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 6 | Sep 11 | Sep 16 | Sep 19 | Sep 22 | Sep 25 | Sep 29 | Oct 1 | Oct 4 |
| 32°F | Sep 18 | Sep 23 | Sep 28 | Oct 1 | Oct 2 | Oct 4 | Oct 7 | Oct 10 | Oct 16 |
| 28°F | Sep 30 | Oct 3 | Oct 6 | Oct 10 | Oct 13 | Oct 16 | Oct 21 | Oct 25 | Oct 30 |
| 24°F | Oct 10 | Oct 17 | Oct 22 | Oct 25 | Oct 29 | Nov 1 | Nov 3 | Nov 7 | Nov 12 |
| 20°F | Oct 27 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 19 | Nov 25 |
| 16°F | Nov 4 | Nov 9 | Nov 13 | Nov 17 | Nov 21 | Nov 25 | Nov 28 | Dec 1 | Dec 6 |
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 | 139 | 131 | 126 | 122 | 118 | 114 | 110 | 105 | 96 |
| 32°F | 162 | 155 | 151 | 146 | 142 | 137 | 133 | 128 | 122 |
| 28°F | 186 | 179 | 174 | 169 | 165 | 161 | 156 | 152 | 144 |
| 24°F | 212 | 205 | 200 | 196 | 191 | 186 | 182 | 176 | 169 |
| 20°F | 236 | 230 | 224 | 219 | 215 | 211 | 206 | 200 | 194 |
| 16°F | 258 | 249 | 243 | 238 | 234 | 230 | 225 | 220 | 213 |
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
- 7,621
- Cooling degree days, base 65°F
- 404
- Growing degree days, base 40°F
- 4,056
- Growing degree days, base 45°F
- 3,064
- Growing degree days, base 50°F
- 2,201
- Growing degree days, base 55°F
- 1,462
- Growing degree days, base 60°F
- 854
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,381 | 0 | 0 |
| February | 1,210 | 0 | 0 |
| March | 1,057 | 0 | 8 |
| April | 666 | 1 | 39 |
| May | 319 | 21 | 210 |
| June | 83 | 86 | 454 |
| July | 25 | 155 | 595 |
| August | 45 | 107 | 527 |
| September | 203 | 31 | 291 |
| October | 554 | 2 | 71 |
| November | 876 | 0 | 6 |
| December | 1,201 | 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 28.1 km from Evart. 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 USC00200779 (Big Rapids Wtp). Public domain.