Uintah County Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Ouray 4NE. 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 2 and the first fall freeze around October 3, a growing season of about 152 days.
- Median at 36°F
- last May 16, first September 25
- Median at 32°F
- last May 2, first October 3
- Median at 28°F
- last April 19, 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 2 | May 27 | May 23 | May 19 | May 16 | May 13 | May 10 | May 6 | May 2 |
| 32°F | May 16 | May 11 | May 7 | May 4 | May 2 | Apr 29 | Apr 27 | Apr 24 | Apr 19 |
| 28°F | May 4 | Apr 29 | Apr 25 | Apr 22 | Apr 19 | Apr 16 | Apr 13 | Apr 9 | Apr 5 |
| 24°F | Apr 20 | Apr 15 | Apr 11 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 27 | Mar 21 |
| 20°F | Apr 6 | Apr 1 | Mar 29 | Mar 25 | Mar 21 | Mar 17 | Mar 13 | Mar 11 | Mar 7 |
| 16°F | Mar 27 | Mar 21 | Mar 16 | Mar 12 | Mar 9 | Mar 6 | Mar 4 | Mar 1 | Feb 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 12 | Sep 16 | Sep 19 | Sep 22 | Sep 25 | Sep 27 | Sep 29 | Oct 2 | Oct 5 |
| 32°F | Sep 21 | Sep 26 | Sep 28 | Oct 1 | Oct 3 | Oct 5 | Oct 7 | Oct 11 | Oct 16 |
| 28°F | Sep 29 | Oct 3 | Oct 6 | Oct 9 | Oct 13 | Oct 15 | Oct 18 | Oct 20 | Oct 25 |
| 24°F | Oct 8 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 25 | Oct 28 | Nov 1 | Nov 4 |
| 20°F | Oct 18 | Oct 23 | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 15 |
| 16°F | Oct 29 | Nov 2 | Nov 5 | Nov 9 | Nov 11 | Nov 15 | Nov 17 | Nov 20 | Nov 24 |
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 | 148 | 143 | 138 | 135 | 131 | 127 | 122 | 118 | 111 |
| 32°F | 169 | 163 | 159 | 155 | 152 | 149 | 146 | 140 | 134 |
| 28°F | 192 | 186 | 181 | 177 | 173 | 170 | 165 | 161 | 153 |
| 24°F | 218 | 211 | 206 | 202 | 197 | 193 | 189 | 185 | 178 |
| 20°F | 244 | 237 | 231 | 227 | 222 | 218 | 214 | 209 | 201 |
| 16°F | 264 | 258 | 253 | 249 | 245 | 241 | 237 | 231 | 224 |
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
- 6,773
- Cooling degree days, base 65°F
- 906
- Growing degree days, base 40°F
- 5,259
- Growing degree days, base 45°F
- 4,125
- Growing degree days, base 50°F
- 3,124
- Growing degree days, base 55°F
- 2,255
- Growing degree days, base 60°F
- 1,518
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,492 | 0 | 0 |
| February | 1,088 | 0 | 0 |
| March | 730 | 0 | 13 |
| April | 432 | 1 | 97 |
| May | 172 | 32 | 334 |
| June | 26 | 180 | 605 |
| July | 1 | 363 | 828 |
| August | 3 | 270 | 732 |
| September | 93 | 59 | 419 |
| October | 469 | 1 | 94 |
| November | 900 | 0 | 3 |
| December | 1,367 | 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 10.7 km from Uintah 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 USC00426568 (Ouray 4NE). Public domain.