Wolfeboro climate

Wolfeboro Frost Dates and Growing Season

NOAA 1991-2020 normals for Lakeport 2, 21.1 km from Wolfeboro, elevation 500 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Lakeport 2. 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 30 and the first fall freeze around October 18, a growing season of about 170 days.

Median at 36°F
last May 10, first October 5
Median at 32°F
last April 30, first October 18
Median at 28°F
last April 17, first November 1

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 23May 18May 16May 12May 10May 8May 5May 3Apr 30
32°FMay 13May 7May 4May 2Apr 30Apr 28Apr 25Apr 23Apr 19
28°FApr 30Apr 25Apr 22Apr 20Apr 17Apr 14Apr 12Apr 10Apr 6
24°FApr 18Apr 14Apr 10Apr 8Apr 6Apr 4Apr 3Apr 1Mar 28
20°FApr 9Apr 5Apr 3Apr 1Mar 31Mar 29Mar 25Mar 21Mar 16
16°FApr 3Mar 31Mar 29Mar 25Mar 22Mar 20Mar 17Mar 14Mar 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°FSep 25Sep 29Oct 1Oct 4Oct 5Oct 8Oct 11Oct 15Oct 19
32°FOct 4Oct 8Oct 12Oct 14Oct 18Oct 20Oct 24Oct 28Nov 3
28°FOct 16Oct 21Oct 26Oct 29Nov 1Nov 3Nov 5Nov 8Nov 13
24°FOct 30Nov 2Nov 6Nov 8Nov 12Nov 14Nov 17Nov 21Nov 25
20°FNov 9Nov 13Nov 17Nov 20Nov 22Nov 25Nov 29Dec 1Dec 6
16°FNov 17Nov 22Nov 26Nov 29Dec 1Dec 4Dec 7Dec 11Dec 16

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°F166160156152149146141137131
32°F188182178173170166163159153
28°F213207203200196192188184176
24°F236229225222219215211207201
20°F257250245241238235230226219
16°F275267263258254251247241235

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
7,103
Cooling degree days, base 65°F
529
Growing degree days, base 40°F
4,439
Growing degree days, base 45°F
3,395
Growing degree days, base 50°F
2,482
Growing degree days, base 55°F
1,694
Growing degree days, base 60°F
1,040

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,36400
February1,17300
March1,02803
April626138
May28716219
June7192472
July9203659
August16163612
September13052375
October468394
November79109
December1,14100

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 21.1 km from Wolfeboro. 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 USC00274480 (Lakeport 2). Public domain.