Brunswick climate

Brunswick Frost Dates and Growing Season

NOAA 1991-2020 normals for Brunswick, 2.3 km from Brunswick, elevation 13 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Brunswick. 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 February 8 and the first fall freeze around December 25, a growing season of about 314 days.

Median at 36°F
last February 27, first December 4
Median at 32°F
last February 8, first December 25
Median at 28°F
last January 24, first January 6

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°FMar 19Mar 13Mar 7Mar 3Feb 27Feb 21Feb 15Feb 8Jan 31
32°FMar 10Mar 1Feb 22Feb 15Feb 8Feb 3Jan 29Jan 20Jan 9
28°FFeb 26Feb 14Feb 5Jan 31Jan 24Jan 18Jan 13Jan 5Dec 28
24°FFeb 12Feb 4Jan 28Jan 21Jan 16Jan 12Jan 6Jan 1Dec 27
20°F–––––––––
16°F–––––––––

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°FNov 14Nov 20Nov 25Dec 1Dec 4Dec 8Dec 15Dec 25Jan 2
32°FNov 26Dec 3Dec 10Dec 19Dec 25Dec 31Jan 4Jan 11Jan 20
28°FDec 9Dec 22Dec 28Jan 1Jan 6Jan 10Jan 16Jan 24Feb 4
24°FDec 18Dec 29Jan 2Jan 9Jan 14Jan 18Jan 24Jan 30Feb 7
20°F–––––––––
16°F–––––––––

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°F315305296288281275268261250
32°F348335329322314307301292278
28°F365365361353343335329322309
24°F365365365365365365362347332
20°F365365365365365365365365365
16°F365365365365365365365365365

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
96% of years
28°F or colder
73% of years
24°F or colder
33% of years
20°F or colder
7% of years
16°F or colder
0% 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
1,400
Cooling degree days, base 65°F
2,698
Growing degree days, base 40°F
10,440
Growing degree days, base 45°F
8,662
Growing degree days, base 50°F
6,955
Growing degree days, base 55°F
5,372
Growing degree days, base 60°F
3,944

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January3947155
February27312192
March16148362
April47130533
May4316777
June0456906
July05521,017
August0525990
September0395844
October30194630
November16748341
December32316208

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 2.3 km from Brunswick. 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 USC00091340 (Brunswick). Public domain.