Barnes County Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Valley City 3 Nnw. 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 September 26, a growing season of about 136 days.
- Median at 36°F
- last May 22, first September 17
- Median at 32°F
- last May 13, first September 26
- 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 4 | May 31 | May 28 | May 25 | May 22 | May 20 | May 17 | May 14 | May 11 |
| 32°F | May 25 | May 22 | May 18 | May 15 | May 13 | May 11 | May 8 | May 5 | May 2 |
| 28°F | May 17 | May 13 | May 10 | May 7 | May 4 | May 2 | Apr 30 | Apr 27 | Apr 21 |
| 24°F | May 10 | May 5 | May 1 | Apr 29 | Apr 26 | Apr 22 | Apr 19 | Apr 16 | Apr 11 |
| 20°F | May 1 | Apr 27 | Apr 23 | Apr 19 | Apr 16 | Apr 13 | Apr 9 | Apr 6 | Apr 3 |
| 16°F | Apr 24 | Apr 17 | Apr 14 | Apr 10 | Apr 7 | Apr 5 | Apr 3 | Mar 31 | Mar 24 |
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 10 | Sep 13 | Sep 15 | Sep 17 | Sep 19 | Sep 21 | Sep 24 | Sep 28 |
| 32°F | Sep 14 | Sep 18 | Sep 21 | Sep 24 | Sep 26 | Sep 28 | Oct 1 | Oct 4 | Oct 8 |
| 28°F | Sep 24 | Sep 28 | Sep 30 | Oct 2 | Oct 5 | Oct 8 | Oct 11 | Oct 15 | Oct 20 |
| 24°F | Oct 1 | Oct 6 | Oct 11 | Oct 14 | Oct 16 | Oct 20 | Oct 23 | Oct 26 | Oct 30 |
| 20°F | Oct 12 | Oct 17 | Oct 22 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 5 | Nov 9 |
| 16°F | Oct 22 | Oct 27 | Oct 31 | Nov 2 | Nov 5 | Nov 7 | Nov 9 | Nov 13 | Nov 16 |
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 | 133 | 128 | 124 | 120 | 116 | 113 | 109 | 105 | 99 |
| 32°F | 153 | 147 | 143 | 139 | 136 | 132 | 129 | 124 | 118 |
| 28°F | 172 | 166 | 162 | 158 | 155 | 152 | 148 | 144 | 137 |
| 24°F | 192 | 186 | 181 | 177 | 174 | 170 | 167 | 162 | 156 |
| 20°F | 211 | 206 | 201 | 196 | 193 | 189 | 185 | 180 | 174 |
| 16°F | 229 | 222 | 217 | 213 | 210 | 206 | 202 | 196 | 190 |
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
- 9,285
- Cooling degree days, base 65°F
- 399
- Growing degree days, base 40°F
- 3,825
- Growing degree days, base 45°F
- 2,905
- Growing degree days, base 50°F
- 2,097
- Growing degree days, base 55°F
- 1,400
- Growing degree days, base 60°F
- 828
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,767 | 0 | 0 |
| February | 1,477 | 0 | 0 |
| March | 1,237 | 0 | 1 |
| April | 737 | 0 | 25 |
| May | 351 | 15 | 190 |
| June | 88 | 82 | 445 |
| July | 27 | 154 | 592 |
| August | 51 | 116 | 530 |
| September | 240 | 30 | 264 |
| October | 655 | 1 | 50 |
| November | 1,101 | 0 | 1 |
| December | 1,553 | 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 4.5 km from Barnes County. 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 USC00328937 (Valley City 3 Nnw). Public domain.