McKinney Acres climate

McKinney Acres Frost Dates and Growing Season

NOAA 1991-2020 normals for Andrews, 5.6 km from McKinney Acres, elevation 3192 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Andrews. 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 18 and the first fall freeze around November 14, a growing season of about 240 days.

Median at 36°F
last April 3, first November 5
Median at 32°F
last March 18, first November 14
Median at 28°F
last March 4, first November 25

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

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 22Oct 28Oct 31Nov 3Nov 5Nov 7Nov 10Nov 13Nov 17
32°FNov 1Nov 5Nov 10Nov 12Nov 14Nov 17Nov 20Nov 24Nov 28
28°FNov 11Nov 14Nov 18Nov 22Nov 25Nov 28Dec 1Dec 5Dec 11
24°FNov 19Nov 26Nov 30Dec 3Dec 7Dec 12Dec 19Dec 25Jan 4
20°FNov 30Dec 5Dec 12Dec 19Dec 25Dec 31Jan 7Jan 16Jan 31
16°FDec 5Dec 12Dec 20Dec 27Jan 1Jan 9Jan 16Jan 25Feb 5

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°F240231225220216212207202195
32°F267258252246240235229222214
28°F296285279273267261256249238
24°F330319309303297289281274264
20°F365354346338330322313305293
16°F365365365365364355346336324

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
88% of years
16°F or colder
52% 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
2,407
Cooling degree days, base 65°F
2,396
Growing degree days, base 40°F
9,224
Growing degree days, base 45°F
7,558
Growing degree days, base 50°F
6,025
Growing degree days, base 55°F
4,649
Growing degree days, base 60°F
3,439

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January607046
February421396
March26021261
April88103469
May12301753
June0486936
July05411,006
August0516981
September7310753
October84107494
November34510176
December583054

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 5.6 km from McKinney Acres. 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 USC00410248 (Andrews). Public domain.