Mountainair climate

Mountainair Frost Dates and Growing Season

NOAA 1991-2020 normals for Mountainair, 1.8 km from Mountainair, elevation 6520 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mountainair. 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 19, a growing season of about 167 days.

Median at 36°F
last May 14, first October 9
Median at 32°F
last May 2, first October 19
Median at 28°F
last April 21, first October 30

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 30May 25May 20May 17May 14May 10May 6May 3Apr 29
32°FMay 18May 13May 9May 5May 2Apr 30Apr 27Apr 23Apr 18
28°FMay 7May 2Apr 28Apr 25Apr 21Apr 18Apr 14Apr 10Apr 4
24°FApr 28Apr 21Apr 17Apr 12Apr 9Apr 5Apr 1Mar 27Mar 19
20°FApr 18Apr 10Apr 5Apr 1Mar 26Mar 20Mar 12Mar 5Feb 26
16°FApr 4Mar 26Mar 16Mar 8Mar 3Feb 27Feb 21Feb 14Feb 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 26Sep 30Oct 3Oct 6Oct 9Oct 12Oct 15Oct 18Oct 22
32°FOct 4Oct 10Oct 14Oct 17Oct 19Oct 22Oct 24Oct 28Nov 1
28°FOct 15Oct 21Oct 24Oct 27Oct 30Nov 1Nov 3Nov 6Nov 11
24°FOct 24Oct 29Nov 1Nov 4Nov 6Nov 9Nov 12Nov 16Nov 21
20°FOct 31Nov 4Nov 9Nov 14Nov 17Nov 20Nov 23Nov 26Dec 1
16°FNov 5Nov 14Nov 19Nov 23Nov 26Nov 29Dec 1Dec 6Dec 12

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°F166160156151147143139134127
32°F188180176172167162159154145
28°F211203197192189185180175168
24°F238230224218212207201195188
20°F269258250244237230225217208
16°F299288279272266258252243229

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
4,823
Cooling degree days, base 65°F
721
Growing degree days, base 40°F
5,600
Growing degree days, base 45°F
4,274
Growing degree days, base 50°F
3,128
Growing degree days, base 55°F
2,159
Growing degree days, base 60°F
1,358

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January93300
February73503
March600033
April3881115
May17027328
June14171607
July1254718
August2199662
September6167457
October3122187
November660020
December94700

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 1.8 km from Mountainair. 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 USC00295965 (Mountainair). Public domain.