Mattituck climate

Mattituck Frost Dates and Growing Season

NOAA 1991-2020 normals for Mattituck, 2 km from Mattituck, elevation 20 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mattituck. 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 19 and the first fall freeze around November 1, a growing season of about 196 days.

Median at 36°F
last May 3, first October 21
Median at 32°F
last April 19, first November 1
Median at 28°F
last April 4, first November 12

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 16May 12May 8May 5May 3Apr 30Apr 27Apr 24Apr 20
32°FMay 4Apr 29Apr 25Apr 22Apr 19Apr 16Apr 14Apr 10Apr 5
28°FApr 19Apr 14Apr 10Apr 7Apr 4Apr 2Mar 31Mar 28Mar 22
24°FApr 4Apr 1Mar 30Mar 27Mar 24Mar 21Mar 17Mar 14Mar 8
20°FMar 29Mar 23Mar 19Mar 16Mar 13Mar 10Mar 7Mar 3Feb 25
16°FMar 20Mar 15Mar 10Mar 6Mar 4Feb 28Feb 24Feb 19Feb 9

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 6Oct 11Oct 14Oct 17Oct 21Oct 24Oct 27Oct 31Nov 4
32°FOct 17Oct 23Oct 26Oct 30Nov 1Nov 3Nov 6Nov 10Nov 14
28°FOct 30Nov 2Nov 6Nov 9Nov 12Nov 15Nov 18Nov 22Nov 28
24°FNov 9Nov 14Nov 18Nov 22Nov 25Nov 28Dec 1Dec 4Dec 10
20°FNov 21Nov 27Dec 1Dec 4Dec 6Dec 10Dec 13Dec 18Dec 25
16°FDec 2Dec 8Dec 12Dec 16Dec 20Dec 24Dec 28Jan 1Jan 7

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°F190182178174170167163158152
32°F214209204200196191186181175
28°F241233228225221217213208202
24°F266259254250246242238233226
20°F292284278273268264260254247
16°F315306301295291287282276267

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
5,530
Cooling degree days, base 65°F
699
Growing degree days, base 40°F
5,185
Growing degree days, base 45°F
3,965
Growing degree days, base 50°F
2,921
Growing degree days, base 55°F
2,027
Growing degree days, base 60°F
1,291

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,07200
February92500
March82906
April518051
May23711247
June40100510
July2259722
August2246708
September6480467
October3204179
November614029
December90702

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 2 km from Mattituck. 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 USC00305142 (Mattituck). Public domain.