Kingston climate

Kingston Frost Dates and Growing Season

NOAA 1991-2020 normals for Epping, 10.7 km from Kingston, elevation 160 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Epping. 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 May 7 and the first fall freeze around October 4, a growing season of about 148 days.

Median at 36°F
last May 19, first September 25
Median at 32°F
last May 7, first October 4
Median at 28°F
last April 24, first October 15

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°FJun 1May 28May 25May 22May 19May 17May 14May 10May 6
32°FMay 21May 17May 14May 10May 7May 4May 1Apr 29Apr 25
28°FMay 8May 3Apr 30Apr 27Apr 24Apr 22Apr 19Apr 16Apr 10
24°FApr 23Apr 18Apr 15Apr 12Apr 9Apr 6Apr 4Apr 2Mar 29
20°FApr 9Apr 5Apr 2Apr 1Mar 30Mar 27Mar 24Mar 20Mar 15
16°FMar 31Mar 29Mar 25Mar 22Mar 20Mar 17Mar 14Mar 11Mar 7

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 12Sep 17Sep 20Sep 23Sep 25Sep 27Sep 30Oct 2Oct 6
32°FSep 22Sep 26Sep 30Oct 1Oct 4Oct 6Oct 8Oct 12Oct 17
28°FOct 1Oct 5Oct 8Oct 11Oct 15Oct 19Oct 23Oct 27Nov 1
24°FOct 12Oct 18Oct 23Oct 27Oct 30Nov 1Nov 4Nov 8Nov 15
20°FOct 29Nov 2Nov 6Nov 10Nov 13Nov 17Nov 20Nov 24Dec 1
16°FNov 12Nov 17Nov 20Nov 24Nov 27Dec 1Dec 3Dec 6Dec 12

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°F144138134130127124120115108
32°F166159155152148145141136130
28°F194187182177172169164159152
24°F221214210206201197193187180
20°F248242237232228224220215208
16°F273265259255251248244239231

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
6,865
Cooling degree days, base 65°F
499
Growing degree days, base 40°F
4,410
Growing degree days, base 45°F
3,340
Growing degree days, base 50°F
2,417
Growing degree days, base 55°F
1,633
Growing degree days, base 60°F
991

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,28600
February1,10200
March96307
April590252
May29618213
June8487454
July12189642
August23150592
September15650349
October481290
November768016
December1,10401

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 10.7 km from Kingston. 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 USC00272800 (Epping). Public domain.