Zapata climate

Zapata Frost Dates and Growing Season

NOAA 1991-2020 normals for Zapata 1 S, 4.4 km from Zapata, elevation 320 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Zapata 1 S. 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 January 19 and the first fall freeze around December 22, a growing season of about 341 days.

Median at 36°F
last February 9, first December 6
Median at 32°F
last January 19, first December 22
Median at 28°F
last January 5, first January 1

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°FMar 7Mar 1Feb 23Feb 16Feb 9Feb 2Jan 27Jan 20Jan 7
32°FFeb 25Feb 14Feb 4Jan 27Jan 19Jan 13Jan 5Dec 29Dec 17
28°FFeb 15Feb 2Jan 23Jan 11Jan 5Jan 2Dec 29Dec 21Dec 13
24°FFeb 1Jan 9Jan 4Jan 2Dec 31Dec 25Dec 20Dec 14Dec 9
20°F–––––––––
16°F–––––––––

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°FNov 17Nov 24Nov 30Dec 3Dec 6Dec 10Dec 17Dec 26Jan 6
32°FNov 28Dec 5Dec 9Dec 15Dec 22Dec 29Jan 4Jan 12Jan 27
28°FDec 8Dec 15Dec 22Dec 30Jan 1Jan 4Jan 10Jan 25Feb 5
24°FDec 8Dec 13Dec 19Dec 25Dec 31Jan 1Jan 3Jan 8Feb 1
20°F–––––––––
16°F–––––––––

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°F340328319311304297289281271
32°F365365358348341335327315302
28°F365365365365365365361351336
24°F365365365365365365365365365
20°F365365365365365365365365365
16°F365365365365365365365365365

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
98% of years
32°F or colder
77% of years
28°F or colder
36% of years
24°F or colder
10% of years
20°F or colder
2% of years
16°F or colder
0% 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
823
Cooling degree days, base 65°F
4,281
Growing degree days, base 40°F
12,589
Growing degree days, base 45°F
10,782
Growing degree days, base 50°F
9,011
Growing degree days, base 55°F
7,313
Growing degree days, base 60°F
5,728

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January26429263
February13468364
March55196609
April10348788
May15401,004
June06601,110
July06931,158
August07101,175
September1532981
October12345799
November97127485
December24934277

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 4.4 km from Zapata. 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 USC00419976 (Zapata 1 S). Public domain.