Arlington climate

Arlington Frost Dates and Growing Season

NOAA 1991-2020 normals for Arlington, 0.3 km from Arlington, elevation 100 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Arlington. 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 22 and the first fall freeze around October 19, a growing season of about 181 days.

Median at 36°F
last May 10, first October 2
Median at 32°F
last April 22, first October 19
Median at 28°F
last March 25, first November 3

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 24May 19May 16May 13May 10May 7May 4May 2Apr 28
32°FMay 6May 2Apr 28Apr 25Apr 22Apr 18Apr 13Apr 9Apr 4
28°FApr 15Apr 6Apr 2Mar 30Mar 25Mar 21Mar 15Mar 11Mar 3
24°FMar 17Mar 11Mar 5Mar 1Feb 26Feb 21Feb 16Feb 7Jan 19
20°FFeb 28Feb 23Feb 15Feb 7Jan 31Jan 19Jan 7Dec 30Dec 13
16°FFeb 17Feb 6Jan 27Jan 14Jan 2Dec 27Dec 18Dec 10Dec 2

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°FSep 17Sep 22Sep 26Sep 30Oct 2Oct 5Oct 8Oct 12Oct 17
32°FOct 3Oct 8Oct 12Oct 16Oct 19Oct 23Oct 25Oct 29Nov 4
28°FOct 19Oct 25Oct 29Oct 31Nov 3Nov 8Nov 12Nov 17Nov 23
24°FOct 31Nov 7Nov 11Nov 16Nov 21Nov 25Nov 30Dec 5Dec 16
20°FNov 14Nov 22Nov 27Dec 1Dec 6Dec 13Dec 21Jan 1Jan 18
16°FNov 23Nov 30Dec 4Dec 8Dec 16Dec 23Dec 31Jan 11Jan 29

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°F164158153150145141136132124
32°F205197191187181176171166159
28°F252243236230224219213206197
24°F310294283274269263257248238
20°F359346334326318308299289276
16°F365365365364353341333324313

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
93% of years
16°F or colder
61% 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
5,834
Cooling degree days, base 65°F
55
Growing degree days, base 40°F
3,734
Growing degree days, base 45°F
2,442
Growing degree days, base 50°F
1,458
Growing degree days, base 55°F
738
Growing degree days, base 60°F
265

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January83701
February72101
March68705
April524029
May3480138
June2117246
July9823391
August10121384
September2403216
October501043
November69904
December86801

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 0.3 km from Arlington. 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 USC00450257 (Arlington). Public domain.