Apache climate

Apache Frost Dates and Growing Season

NOAA 1991-2020 normals for Apache 4ENE Mesonet, 7.1 km from Apache, elevation 1443 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Apache 4ENE Mesonet. 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 3 and the first fall freeze around November 3, a growing season of about 213 days.

Median at 36°F
last April 15, first October 26
Median at 32°F
last April 3, first November 3
Median at 28°F
last March 22, first November 12

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 30Apr 25Apr 21Apr 18Apr 15Apr 12Apr 8Apr 4Mar 30
32°FApr 21Apr 15Apr 10Apr 7Apr 3Mar 31Mar 28Mar 23Mar 16
28°FApr 9Apr 4Mar 31Mar 27Mar 22Mar 18Mar 14Mar 9Mar 2
24°FMar 29Mar 21Mar 16Mar 12Mar 8Mar 5Mar 2Feb 26Feb 19
20°FMar 16Mar 9Mar 5Mar 1Feb 26Feb 22Feb 18Feb 10Jan 31
16°FMar 6Mar 1Feb 23Feb 18Feb 11Feb 5Jan 30Jan 23Jan 9

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 20Oct 23Oct 26Oct 29Nov 1Nov 4Nov 8
32°FOct 20Oct 25Oct 29Nov 1Nov 3Nov 6Nov 10Nov 13Nov 18
28°FOct 26Nov 1Nov 5Nov 9Nov 12Nov 16Nov 19Nov 24Nov 30
24°FNov 3Nov 9Nov 14Nov 19Nov 23Nov 27Dec 1Dec 5Dec 10
20°FNov 14Nov 21Nov 26Dec 1Dec 5Dec 9Dec 14Dec 21Dec 29
16°FNov 23Dec 1Dec 7Dec 14Dec 21Dec 26Jan 2Jan 10Jan 20

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°F216208203198193190185180173
32°F237229224218213209204198190
28°F260251245240234230225219209
24°F287275269264258252247241230
20°F317305297289282276270262252
16°F353341332323315307300291279

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
96% 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
3,523
Cooling degree days, base 65°F
1,949
Growing degree days, base 40°F
7,937
Growing degree days, base 45°F
6,442
Growing degree days, base 50°F
5,092
Growing degree days, base 55°F
3,892
Growing degree days, base 60°F
2,844

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January806015
February624149
March4349148
April19938312
May50172588
June0379829
July0513978
August0502967
September17261695
October17068379
November4595112
December764021

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 7.1 km from Apache. 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 USC00340264 (Apache 4ENE Mesonet). Public domain.