Onida Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Onida 4 Nw. 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 2, a growing season of about 147 days.
- Median at 36°F
- last May 17, first September 23
- Median at 32°F
- last May 8, first October 2
- Median at 28°F
- last April 29, first October 11
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 29 | May 25 | May 22 | May 19 | May 17 | May 14 | May 11 | May 8 | May 4 |
| 32°F | May 22 | May 17 | May 14 | May 10 | May 8 | May 5 | May 3 | Apr 30 | Apr 25 |
| 28°F | May 13 | May 8 | May 4 | May 1 | Apr 29 | Apr 26 | Apr 23 | Apr 18 | Apr 14 |
| 24°F | May 3 | Apr 30 | Apr 25 | Apr 21 | Apr 18 | Apr 15 | Apr 12 | Apr 8 | Apr 3 |
| 20°F | Apr 24 | Apr 18 | Apr 14 | Apr 11 | Apr 7 | Apr 5 | Apr 2 | Mar 30 | Mar 22 |
| 16°F | Apr 14 | Apr 9 | Apr 5 | Apr 1 | Mar 30 | Mar 26 | Mar 22 | Mar 17 | Mar 11 |
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 21 | Sep 23 | Sep 26 | Sep 28 | Oct 1 | Oct 6 |
| 32°F | Sep 19 | Sep 23 | Sep 27 | Sep 29 | Oct 2 | Oct 5 | Oct 7 | Oct 11 | Oct 15 |
| 28°F | Sep 27 | Oct 1 | Oct 4 | Oct 8 | Oct 11 | Oct 14 | Oct 17 | Oct 20 | Oct 24 |
| 24°F | Oct 5 | Oct 10 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Oct 30 | Nov 4 |
| 20°F | Oct 16 | Oct 20 | Oct 24 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 13 |
| 16°F | Oct 23 | Oct 28 | Nov 1 | Nov 4 | Nov 6 | Nov 10 | Nov 13 | Nov 16 | Nov 22 |
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 | 147 | 141 | 137 | 133 | 130 | 126 | 123 | 118 | 113 |
| 32°F | 165 | 159 | 154 | 151 | 147 | 143 | 139 | 134 | 128 |
| 28°F | 183 | 177 | 173 | 169 | 165 | 161 | 157 | 152 | 145 |
| 24°F | 205 | 198 | 193 | 188 | 184 | 180 | 175 | 170 | 162 |
| 20°F | 223 | 215 | 210 | 205 | 201 | 197 | 193 | 189 | 181 |
| 16°F | 243 | 236 | 230 | 225 | 220 | 215 | 211 | 206 | 197 |
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
- 7,660
- Cooling degree days, base 65°F
- 782
- Growing degree days, base 40°F
- 4,756
- Growing degree days, base 45°F
- 3,720
- Growing degree days, base 50°F
- 2,802
- Growing degree days, base 55°F
- 2,004
- Growing degree days, base 60°F
- 1,329
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,489 | 0 | 0 |
| February | 1,233 | 0 | 1 |
| March | 985 | 0 | 11 |
| April | 587 | 2 | 64 |
| May | 272 | 27 | 256 |
| June | 55 | 133 | 529 |
| July | 8 | 298 | 755 |
| August | 17 | 235 | 683 |
| September | 143 | 82 | 399 |
| October | 538 | 5 | 98 |
| November | 962 | 0 | 6 |
| December | 1,372 | 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 7.2 km from Onida. 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 USC00396292 (Onida 4 Nw). Public domain.