Mesilla climate

Mesilla Frost Dates and Growing Season

NOAA 1991-2020 normals for State Univ, 4.1 km from Mesilla, elevation 3886 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for State Univ. 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 March 12 and the first fall freeze around November 13, a growing season of about 241 days.

Median at 36°F
last April 1, first November 4
Median at 32°F
last March 12, first November 13
Median at 28°F
last February 26, first November 24

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°FApr 19Apr 13Apr 8Apr 5Apr 1Mar 28Mar 23Mar 19Mar 12
32°FApr 2Mar 26Mar 20Mar 16Mar 12Mar 8Mar 4Feb 28Feb 23
28°FMar 15Mar 8Mar 4Feb 28Feb 26Feb 21Feb 17Feb 12Feb 4
24°FMar 1Feb 20Feb 14Feb 9Feb 5Feb 1Jan 27Jan 21Jan 11
20°FFeb 13Feb 4Jan 28Jan 18Jan 12Jan 6Dec 31Dec 23Dec 10
16°FFeb 6Jan 27Jan 18Jan 10Jan 6Jan 2Dec 28Dec 21Dec 12

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°FOct 21Oct 26Oct 30Nov 1Nov 4Nov 6Nov 8Nov 11Nov 15
32°FOct 30Nov 4Nov 7Nov 10Nov 13Nov 15Nov 18Nov 21Nov 24
28°FNov 9Nov 15Nov 19Nov 22Nov 24Nov 27Nov 30Dec 3Dec 8
24°FNov 21Nov 27Nov 30Dec 3Dec 6Dec 10Dec 14Dec 19Dec 29
20°FNov 30Dec 6Dec 11Dec 17Dec 22Dec 27Jan 2Jan 12Jan 23
16°FDec 7Dec 15Dec 21Dec 28Jan 2Jan 6Jan 11Jan 22Feb 2

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°F234226222218214209205200193
32°F262256250245241236230225216
28°F296288281276270265259253246
24°F335325318310305300293287275
20°F365365358353347341333325311
16°F365365365365365365365362349

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
76% of years
16°F or colder
28% 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
2,675
Cooling degree days, base 65°F
2,059
Growing degree days, base 40°F
8,580
Growing degree days, base 45°F
6,914
Growing degree days, base 50°F
5,425
Growing degree days, base 55°F
4,132
Growing degree days, base 60°F
3,013

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January643012
February454052
March3053189
April12033366
May18193640
June0449898
July05381,003
August0485950
September3296743
October9461437
November3841121
December654015

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 4.1 km from Mesilla. 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 USC00298535 (State Univ). Public domain.