Ossipee climate

Ossipee Frost Dates and Growing Season

NOAA 1991-2020 normals for Burlington Fire Stn #5, 13.7 km from Ossipee, elevation 660 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Burlington Fire Stn #5. 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 March 29 and the first fall freeze around November 9, a growing season of about 226 days.

Median at 36°F
last April 10, first October 30
Median at 32°F
last March 29, first November 9
Median at 28°F
last March 15, first November 23

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 2Apr 23Apr 18Apr 13Apr 10Apr 6Apr 3Mar 30Mar 25
32°FApr 15Apr 7Apr 4Apr 1Mar 29Mar 25Mar 20Mar 16Mar 8
28°FApr 3Mar 29Mar 23Mar 19Mar 15Mar 10Mar 5Feb 28Feb 22
24°FMar 22Mar 14Mar 9Mar 4Feb 28Feb 24Feb 19Feb 11Feb 2
20°FMar 9Mar 2Feb 23Feb 14Feb 7Feb 2Jan 29Jan 20Jan 10
16°FMar 2Feb 13Feb 3Jan 31Jan 26Jan 20Jan 15Jan 9Dec 31

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 17Oct 22Oct 25Oct 28Oct 30Nov 1Nov 4Nov 7Nov 10
32°FOct 26Oct 31Nov 3Nov 6Nov 9Nov 11Nov 14Nov 19Nov 25
28°FNov 6Nov 11Nov 15Nov 19Nov 23Nov 27Dec 1Dec 5Dec 14
24°FNov 20Nov 28Dec 1Dec 7Dec 11Dec 18Dec 23Dec 31Jan 7
20°FDec 7Dec 14Dec 21Dec 27Jan 1Jan 6Jan 12Jan 17Jan 29
16°FDec 20Dec 27Jan 1Jan 6Jan 11Jan 16Jan 20Jan 28Feb 8

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°F224217212208203198193186179
32°F253243237232226222217211200
28°F284273266260255249243235225
24°F319308299294288280273266255
20°F357343333325318311305299288
16°F365365365358350341333323308

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
95% of years
16°F or colder
65% 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
3,287
Cooling degree days, base 65°F
1,655
Growing degree days, base 40°F
7,715
Growing degree days, base 45°F
6,173
Growing degree days, base 50°F
4,793
Growing degree days, base 55°F
3,581
Growing degree days, base 60°F
2,536

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January743026
February590137
March4447130
April19840309
May52150564
June4331777
July0451916
August0408873
September15218652
October16544351
November4264117
December651142

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 13.7 km from Ossipee. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00311239 (Burlington Fire Stn #5). Public domain.