Andrews climate

Andrews Frost Dates and Growing Season

NOAA 1991-2020 normals for Andrews, 1.3 km from Andrews, elevation 35 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 23 and the first fall freeze around November 13, a growing season of about 237 days.

Median at 36°F
last April 3, first November 3
Median at 32°F
last March 23, first November 13
Median at 28°F
last March 8, 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 14Apr 10Apr 7Apr 3Mar 31Mar 29Mar 25Mar 19
32°FApr 7Apr 1Mar 29Mar 26Mar 23Mar 19Mar 16Mar 10Mar 4
28°FMar 27Mar 22Mar 17Mar 13Mar 8Mar 4Feb 28Feb 23Feb 13
24°FMar 17Mar 7Mar 2Feb 26Feb 18Feb 11Feb 5Jan 30Jan 19
20°FMar 2Feb 21Feb 10Feb 2Jan 30Jan 24Jan 18Jan 11Jan 1
16°FFeb 8Jan 31Jan 28Jan 22Jan 18Jan 12Jan 7Jan 2Dec 26

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 27Oct 30Nov 1Nov 3Nov 5Nov 7Nov 11Nov 17
32°FNov 1Nov 4Nov 6Nov 9Nov 13Nov 16Nov 20Nov 25Dec 1
28°FNov 7Nov 12Nov 17Nov 21Nov 25Nov 29Dec 2Dec 8Dec 20
24°FNov 19Nov 26Dec 1Dec 7Dec 12Dec 21Dec 28Jan 4Jan 14
20°FDec 2Dec 11Dec 20Dec 26Jan 1Jan 5Jan 10Jan 18Jan 29
16°FDec 18Dec 26Dec 31Jan 4Jan 8Jan 12Jan 17Jan 23Feb 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°F236227221216212208205200194
32°F264252246241237232227221213
28°F294283274268262257251244236
24°F333319310303297289282274264
20°F365356346337331324316306297
16°F365365365365365356346336326

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
99% of years
20°F or colder
83% of years
16°F or colder
44% 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
2,485
Cooling degree days, base 65°F
1,951
Growing degree days, base 40°F
8,692
Growing degree days, base 45°F
7,033
Growing degree days, base 50°F
5,518
Growing degree days, base 55°F
4,158
Growing degree days, base 60°F
2,964

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January592269
February466383
March32813203
April13159384
May23196639
June1368817
July0482947
August0440905
September6282726
October9488462
November32914186
December516597

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 1.3 km from Andrews. 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 USC00380184 (Andrews). Public domain.