Sandy Hook climate

Sandy Hook Frost Dates and Growing Season

NOAA 1991-2020 normals for W Liberty 3NW, 22.3 km from Sandy Hook, elevation 780 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for W Liberty 3NW. 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 29 and the first fall freeze around October 16, a growing season of about 169 days.

Median at 36°F
last May 7, first October 6
Median at 32°F
last April 29, first October 16
Median at 28°F
last April 17, first October 26

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 18May 14May 10May 7May 4Apr 30Apr 27Apr 21
32°FMay 16May 10May 5May 1Apr 29Apr 25Apr 21Apr 18Apr 13
28°FMay 7May 1Apr 25Apr 21Apr 17Apr 14Apr 11Apr 7Apr 2
24°FApr 22Apr 16Apr 11Apr 7Apr 4Apr 1Mar 30Mar 25Mar 19
20°FApr 8Apr 2Mar 31Mar 27Mar 23Mar 19Mar 14Mar 9Feb 28
16°FMar 28Mar 21Mar 17Mar 12Mar 8Mar 3Feb 28Feb 22Feb 14

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 25Sep 30Oct 2Oct 5Oct 6Oct 9Oct 12Oct 15Oct 20
32°FOct 3Oct 7Oct 10Oct 13Oct 16Oct 19Oct 22Oct 26Oct 31
28°FOct 12Oct 16Oct 19Oct 22Oct 26Oct 29Nov 1Nov 3Nov 8
24°FOct 22Oct 27Oct 30Nov 1Nov 4Nov 7Nov 10Nov 13Nov 18
20°FOct 31Nov 4Nov 7Nov 11Nov 14Nov 17Nov 22Nov 28Dec 4
16°FNov 7Nov 14Nov 18Nov 24Nov 29Dec 1Dec 7Dec 13Dec 24

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°F170165160156152148145140133
32°F190182178173169165160154148
28°F212204199194189186181174167
24°F236228222217212209204199190
20°F266257250243238232228222214
16°F299287279272265259254247237

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
100% of years
16°F or colder
100% 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
4,891
Cooling degree days, base 65°F
942
Growing degree days, base 40°F
5,970
Growing degree days, base 45°F
4,658
Growing degree days, base 50°F
3,502
Growing degree days, base 55°F
2,504
Growing degree days, base 60°F
1,650

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,00108
February818010
March666155
April34912181
May14167395
June17188621
July2293756
August3259721
September59111503
October32212200
November630041
December884013

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 22.3 km from Sandy Hook. 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 USC00158551 (W Liberty 3NW). Public domain.