Cochise County climate

Cochise County Frost Dates and Growing Season

NOAA 1991-2020 normals for Pearce - Sunsites, 10.3 km from Cochise County, elevation 4350 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Pearce - Sunsites. 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 14 and the first fall freeze around November 2, a growing season of about 200 days.

Median at 36°F
last April 28, first October 24
Median at 32°F
last April 14, first November 2
Median at 28°F
last March 27, first November 13

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

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°F198191186182178174170166160
32°F222215210205200196191185178
28°F254245238233228223217210202
24°F298286279273267260254246235
20°F341331322313305299293285275
16°F365365363354346339334326313

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
99% of years
16°F or colder
71% 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
2,827
Cooling degree days, base 65°F
1,582
Growing degree days, base 40°F
7,942
Growing degree days, base 45°F
6,277
Growing degree days, base 50°F
4,797
Growing degree days, base 55°F
3,536
Growing degree days, base 60°F
2,470

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January634012
February479040
March3591142
April17614295
May43125547
June1364813
July0429894
August0377842
September3230677
October10742403
November3871118
December640016

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 10.3 km from Cochise County. 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 USC00026353 (Pearce - Sunsites). Public domain.