Sierra Blanca climate

Sierra Blanca Frost Dates and Growing Season

NOAA 1991-2020 normals for Ft Hancock 8SSE, 36.6 km from Sierra Blanca, elevation 3493 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Ft Hancock 8SSE. 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 29 and the first fall freeze around November 6, a growing season of about 221 days.

Median at 36°F
last April 13, first October 30
Median at 32°F
last March 29, first November 6
Median at 28°F
last March 11, first November 15

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 29Apr 25Apr 20Apr 16Apr 13Apr 10Apr 6Apr 3Mar 29
32°FApr 15Apr 7Apr 4Apr 1Mar 29Mar 25Mar 21Mar 16Mar 10
28°FMar 30Mar 25Mar 20Mar 16Mar 11Mar 8Mar 5Mar 1Feb 23
24°FMar 15Mar 9Mar 5Mar 1Feb 27Feb 22Feb 17Feb 12Feb 7
20°FMar 5Feb 26Feb 20Feb 15Feb 11Feb 6Feb 2Jan 28Jan 19
16°FFeb 16Feb 7Feb 3Jan 29Jan 23Jan 17Jan 7Dec 31Dec 20

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 17Oct 21Oct 24Oct 27Oct 30Nov 1Nov 3Nov 5Nov 8
32°FOct 24Oct 30Nov 1Nov 4Nov 6Nov 9Nov 11Nov 14Nov 17
28°FNov 1Nov 6Nov 10Nov 13Nov 15Nov 18Nov 20Nov 23Nov 27
24°FNov 10Nov 15Nov 19Nov 22Nov 25Nov 28Dec 1Dec 5Dec 10
20°FNov 20Nov 26Nov 30Dec 3Dec 6Dec 10Dec 14Dec 20Dec 27
16°FNov 30Dec 6Dec 11Dec 16Dec 21Dec 26Jan 1Jan 9Jan 26

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°F218211205201197193189184177
32°F243236231226221217212206198
28°F267262256251247243238233224
24°F295287281276271266262255247
20°F328318309304298292287280270
16°F365358349341335329322312301

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
89% 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
2,545
Cooling degree days, base 65°F
2,275
Growing degree days, base 40°F
8,938
Growing degree days, base 45°F
7,279
Growing degree days, base 50°F
5,773
Growing degree days, base 55°F
4,447
Growing degree days, base 60°F
3,279

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January649016
February433071
March2737224
April8863427
May12252705
June0496946
July05521,017
August0501966
September4313759
October7787478
November3634143
December646021

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 36.6 km from Sierra Blanca. 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 USC00413266 (Ft Hancock 8SSE). Public domain.