Kingston climate

Kingston Frost Dates and Growing Season

NOAA 1991-2020 normals for Plymouth-Kingston, 2.7 km from Kingston, elevation 45 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Plymouth-Kingston. 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 15 and the first fall freeze around November 1, a growing season of about 198 days.

Median at 36°F
last April 30, first October 20
Median at 32°F
last April 15, first November 1
Median at 28°F
last April 3, first November 13

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 11May 6May 3May 1Apr 30Apr 27Apr 24Apr 21Apr 16
32°FApr 28Apr 24Apr 21Apr 18Apr 15Apr 13Apr 9Apr 6Apr 2
28°FApr 18Apr 12Apr 8Apr 5Apr 3Apr 1Mar 30Mar 26Mar 19
24°FApr 6Apr 2Mar 31Mar 28Mar 25Mar 21Mar 17Mar 13Mar 8
20°FMar 30Mar 26Mar 21Mar 17Mar 14Mar 11Mar 7Mar 4Feb 27
16°FMar 22Mar 16Mar 12Mar 8Mar 4Mar 1Feb 25Feb 19Feb 10

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 10Oct 13Oct 17Oct 20Oct 23Oct 26Oct 29Nov 3
32°FOct 17Oct 23Oct 27Oct 30Nov 1Nov 3Nov 6Nov 10Nov 14
28°FOct 31Nov 4Nov 7Nov 10Nov 13Nov 16Nov 19Nov 23Nov 30
24°FNov 12Nov 17Nov 20Nov 24Nov 27Dec 1Dec 3Dec 7Dec 14
20°FNov 24Nov 30Dec 2Dec 5Dec 7Dec 12Dec 17Dec 22Dec 29
16°FDec 5Dec 10Dec 14Dec 18Dec 22Dec 25Dec 30Jan 3Jan 10

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°F193186181177174170166161156
32°F218212207202198195191186179
28°F247239233228224220216210202
24°F272264258252248244239234226
20°F294286281276271266261254247
16°F316307301297293288283277268

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
5,309
Cooling degree days, base 65°F
805
Growing degree days, base 40°F
5,428
Growing degree days, base 45°F
4,173
Growing degree days, base 50°F
3,094
Growing degree days, base 55°F
2,174
Growing degree days, base 60°F
1,412

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,04203
February89501
March805011
April488272
May22624272
June43142549
July4284745
August3243705
September5997488
October30311198
November578043
December86506

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 2.7 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 USC00196486 (Plymouth-Kingston). Public domain.