Moab climate

Moab Frost Dates and Growing Season

NOAA 1991-2020 normals for Moab, 0.4 km from Moab, elevation 4053 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Moab. 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 April 11 and the first fall freeze around October 23, a growing season of about 192 days.

Median at 36°F
last April 26, first October 11
Median at 32°F
last April 11, first October 23
Median at 28°F
last March 24, first November 1

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°FMay 12May 5May 2Apr 29Apr 26Apr 23Apr 20Apr 16Apr 10
32°FApr 28Apr 21Apr 18Apr 14Apr 11Apr 7Apr 3Mar 31Mar 25
28°FApr 12Apr 5Apr 1Mar 29Mar 24Mar 19Mar 16Mar 12Mar 7
24°FMar 25Mar 16Mar 12Mar 8Mar 6Mar 2Feb 28Feb 25Feb 18
20°FMar 7Mar 2Feb 27Feb 24Feb 20Feb 16Feb 12Feb 6Jan 31
16°FFeb 25Feb 16Feb 12Feb 7Feb 3Jan 31Jan 27Jan 19Jan 9

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 30Oct 3Oct 5Oct 8Oct 11Oct 14Oct 17Oct 21Oct 24
32°FOct 8Oct 13Oct 17Oct 20Oct 23Oct 25Oct 28Nov 1Nov 4
28°FOct 18Oct 23Oct 27Oct 31Nov 1Nov 4Nov 7Nov 11Nov 15
24°FOct 28Nov 3Nov 7Nov 10Nov 13Nov 16Nov 18Nov 21Nov 25
20°FNov 8Nov 14Nov 18Nov 21Nov 24Nov 27Dec 1Dec 4Dec 10
16°FNov 20Nov 26Nov 30Dec 3Dec 7Dec 11Dec 15Dec 20Dec 27

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°F187180176172168165161156149
32°F214207201196192187183177172
28°F243236231226220216210205198
24°F271264258254250245240235227
20°F301293286281277272266260253
16°F337326317310305300294286277

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
99% 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
4,406
Cooling degree days, base 65°F
1,732
Growing degree days, base 40°F
7,079
Growing degree days, base 45°F
5,728
Growing degree days, base 50°F
4,517
Growing degree days, base 55°F
3,450
Growing degree days, base 60°F
2,526

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,00900
February71008
March463192
April24316242
May71122517
June4346792
July05501,015
August0465930
September24210636
October25122259
November639026
December99301

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 0.4 km from Moab. 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 USC00425733 (Moab). Public domain.