Island Pond climate

Island Pond Frost Dates and Growing Season

NOAA 1991-2020 normals for Island Pond, 0.8 km from Island Pond, elevation 1200 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Island Pond. 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 19 and the first fall freeze around September 29, a growing season of about 129 days.

Median at 36°F
last June 2, first September 15
Median at 32°F
last May 19, first September 29
Median at 28°F
last May 5, first October 9

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 16Jun 11Jun 8Jun 5Jun 2May 31May 28May 25May 20
32°FJun 3May 30May 26May 22May 19May 17May 13May 9May 3
28°FMay 19May 15May 11May 8May 5May 2Apr 30Apr 27Apr 23
24°FMay 5May 1Apr 28Apr 26Apr 23Apr 21Apr 18Apr 15Apr 10
20°FApr 24Apr 21Apr 18Apr 16Apr 13Apr 11Apr 8Apr 6Apr 3
16°FApr 18Apr 13Apr 10Apr 8Apr 6Apr 4Apr 2Apr 1Mar 29

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 2Sep 6Sep 9Sep 12Sep 15Sep 18Sep 22Sep 25Sep 30
32°FSep 14Sep 19Sep 23Sep 26Sep 29Oct 1Oct 4Oct 7Oct 13
28°FSep 25Oct 1Oct 3Oct 6Oct 9Oct 13Oct 16Oct 21Oct 28
24°FOct 7Oct 12Oct 17Oct 20Oct 23Oct 27Oct 31Nov 3Nov 7
20°FOct 18Oct 25Oct 30Nov 1Nov 4Nov 6Nov 9Nov 13Nov 18
16°FNov 1Nov 4Nov 8Nov 11Nov 13Nov 16Nov 18Nov 22Nov 26

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°F12311611110710399959184
32°F151144138133129125122116108
28°F177169164159155151146141134
24°F202194190186181177172167160
20°F222216211207204200196191186
16°F236231226222220217213209203

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
8,880
Cooling degree days, base 65°F
217
Growing degree days, base 40°F
3,448
Growing degree days, base 45°F
2,528
Growing degree days, base 50°F
1,732
Growing degree days, base 55°F
1,064
Growing degree days, base 60°F
551

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,59800
February1,39200
March1,24301
April776120
May4058145
June15342343
July5885491
August8561441
September26220235
October619151
November94405
December1,34500

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 0.8 km from Island Pond. 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 USC00434120 (Island Pond). Public domain.