Duchesne climate

Duchesne Frost Dates and Growing Season

NOAA 1991-2020 normals for Duchesne, 0.9 km from Duchesne, elevation 5551 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Duchesne. 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 6 and the first fall freeze around October 5, a growing season of about 150 days.

Median at 36°F
last May 22, first September 26
Median at 32°F
last May 6, first October 5
Median at 28°F
last April 22, first October 16

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.

Threshold10%20%30%40%50%60%70%80%90%
36°FJun 10Jun 4May 31May 26May 22May 19May 16May 12May 7
32°FMay 26May 18May 13May 10May 6May 3Apr 30Apr 27Apr 22
28°FMay 7May 1Apr 28Apr 25Apr 22Apr 19Apr 16Apr 13Apr 9
24°FApr 22Apr 17Apr 13Apr 10Apr 8Apr 5Apr 3Mar 31Mar 25
20°FApr 11Apr 5Apr 2Mar 30Mar 25Mar 21Mar 16Mar 12Mar 6
16°FMar 31Mar 23Mar 16Mar 12Mar 8Mar 5Mar 2Feb 27Feb 19

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.

Threshold10%20%30%40%50%60%70%80%90%
36°FSep 13Sep 19Sep 22Sep 24Sep 26Sep 28Sep 30Oct 3Oct 7
32°FSep 24Sep 28Oct 1Oct 3Oct 5Oct 7Oct 11Oct 14Oct 18
28°FOct 2Oct 7Oct 11Oct 14Oct 16Oct 18Oct 21Oct 24Oct 28
24°FOct 13Oct 18Oct 21Oct 24Oct 26Oct 28Oct 31Nov 3Nov 6
20°FOct 21Oct 26Oct 30Nov 1Nov 4Nov 6Nov 9Nov 13Nov 17
16°FOct 31Nov 4Nov 8Nov 11Nov 14Nov 18Nov 20Nov 23Nov 28

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.

Threshold10%20%30%40%50%60%70%80%90%
36°F144138133129125120116111102
32°F169163158154150146141136127
28°F193187183179174171167162156
24°F218212207204200196192188180
20°F246238233228224219214209202
16°F271264258254250245240234225

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
6,663
Cooling degree days, base 65°F
533
Growing degree days, base 40°F
4,648
Growing degree days, base 45°F
3,529
Growing degree days, base 50°F
2,560
Growing degree days, base 55°F
1,740
Growing degree days, base 60°F
1,063

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,33400
February1,00700
March74309
April495062
May24811247
June5695490
July3232694
August9166622
September13029355
October489080
November87603
December1,27400

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 0.9 km from Duchesne. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00422253 (Duchesne). Public domain.