Aneth climate

Aneth Frost Dates and Growing Season

NOAA 1991-2020 normals for Hovenweep Nm, 21.3 km from Aneth, elevation 5240 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hovenweep Nm. 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 10, a growing season of about 159 days.

Median at 36°F
last May 16, first October 2
Median at 32°F
last May 2, first October 10
Median at 28°F
last April 21, first October 20

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 4May 30May 24May 20May 16May 13May 9May 5May 2
32°FMay 21May 14May 9May 5May 2Apr 30Apr 28Apr 24Apr 19
28°FMay 7May 1Apr 28Apr 24Apr 21Apr 17Apr 14Apr 10Apr 6
24°FApr 23Apr 17Apr 12Apr 9Apr 6Apr 3Mar 31Mar 25Mar 19
20°FApr 9Apr 4Mar 30Mar 24Mar 20Mar 15Mar 10Mar 5Feb 26
16°FMar 23Mar 14Mar 8Mar 4Feb 28Feb 24Feb 17Feb 12Feb 3

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 21Sep 25Sep 28Oct 1Oct 2Oct 5Oct 7Oct 11Oct 15
32°FSep 27Oct 1Oct 4Oct 7Oct 10Oct 13Oct 16Oct 20Oct 24
28°FOct 5Oct 10Oct 14Oct 17Oct 20Oct 23Oct 27Oct 31Nov 4
24°FOct 14Oct 20Oct 25Oct 29Nov 1Nov 3Nov 6Nov 10Nov 14
20°FOct 26Nov 1Nov 4Nov 7Nov 10Nov 13Nov 16Nov 19Nov 23
16°FNov 6Nov 11Nov 15Nov 18Nov 21Nov 23Nov 26Nov 29Dec 4

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°F156151146142138135129124117
32°F178172167163159155151145137
28°F202194189184180177172166158
24°F229220214210205200196190182
20°F257249242237232228223216208
16°F290282275269264259253245236

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
5,229
Cooling degree days, base 65°F
1,141
Growing degree days, base 40°F
5,864
Growing degree days, base 45°F
4,618
Growing degree days, base 50°F
3,535
Growing degree days, base 55°F
2,600
Growing degree days, base 60°F
1,807

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,05900
February78501
March636022
April4031116
May15644361
June18220653
July0417882
August1342806
September51114514
October3473166
November717013
December1,05700

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 21.3 km from Aneth. 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 USC00424100 (Hovenweep Nm). Public domain.