East Hampton climate

East Hampton Frost Dates and Growing Season

NOAA 1991-2020 normals for Langley AFB, 5.4 km from East Hampton, elevation 10 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Langley AFB. 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 24 and the first fall freeze around November 15, a growing season of about 238 days.

Median at 36°F
last April 4, first November 5
Median at 32°F
last March 24, first November 15
Median at 28°F
last March 10, first November 28

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 18Apr 13Apr 9Apr 6Apr 4Apr 1Mar 29Mar 26Mar 22
32°FApr 6Apr 2Mar 30Mar 27Mar 24Mar 20Mar 17Mar 13Mar 9
28°FMar 28Mar 21Mar 17Mar 13Mar 10Mar 7Mar 3Feb 27Feb 22
24°FMar 13Mar 7Mar 3Feb 28Feb 25Feb 20Feb 14Feb 8Feb 1
20°FMar 2Feb 24Feb 17Feb 10Feb 5Feb 1Jan 28Jan 21Jan 11
16°FFeb 17Feb 7Feb 2Jan 30Jan 26Jan 21Jan 16Jan 10Jan 3

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 25Oct 30Nov 1Nov 3Nov 5Nov 7Nov 10Nov 13Nov 18
32°FNov 3Nov 7Nov 10Nov 13Nov 15Nov 19Nov 23Nov 27Dec 2
28°FNov 10Nov 15Nov 20Nov 24Nov 28Dec 1Dec 5Dec 10Dec 20
24°FNov 23Nov 30Dec 5Dec 11Dec 18Dec 23Dec 29Jan 3Jan 12
20°FDec 9Dec 18Dec 26Dec 30Jan 3Jan 8Jan 13Jan 18Jan 28
16°FDec 21Dec 30Jan 4Jan 8Jan 13Jan 16Jan 20Jan 26Feb 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°F234227223219216212209203198
32°F261253247243238234229224217
28°F292283277271266261254248240
24°F325316309303297291285277267
20°F360344335330325318312306298
16°F365365365357348341334329319

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
69% 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
3,461
Cooling degree days, base 65°F
1,592
Growing degree days, base 40°F
7,516
Growing degree days, base 45°F
5,997
Growing degree days, base 50°F
4,646
Growing degree days, base 55°F
3,464
Growing degree days, base 60°F
2,447

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January758027
February626024
March502597
April24841275
May66120520
June5305750
July0442906
August0397862
September13229666
October16348357
November4235121
December656142

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 5.4 km from East Hampton. 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 USW00013702 (Langley AFB). Public domain.