Bangor climate

Bangor Frost Dates and Growing Season

NOAA 1991-2020 normals for Dobbins 1 S, 17.9 km from Bangor, elevation 1640 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Dobbins 1 S. 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 1 and the first fall freeze around November 17, a growing season of about 229 days.

Median at 36°F
last April 23, first November 1
Median at 32°F
last April 1, first November 17
Median at 28°F
last February 27, first December 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 12May 5Apr 30Apr 27Apr 23Apr 19Apr 14Apr 10Apr 4
32°FApr 22Apr 14Apr 9Apr 5Apr 1Mar 27Mar 20Mar 15Mar 4
28°FMar 27Mar 14Mar 7Mar 2Feb 27Feb 22Feb 15Feb 6Jan 24
24°FFeb 28Feb 24Feb 18Feb 9Feb 1Jan 22Jan 13Jan 3Dec 25
20°FFeb 23Feb 12Jan 31Jan 20Jan 12Jan 3Dec 31Dec 24Dec 12
16°FFeb 9Jan 18Jan 13Jan 5Jan 2Dec 31Dec 28Dec 19Dec 8

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 12Oct 19Oct 25Oct 28Nov 1Nov 3Nov 6Nov 11Nov 16
32°FOct 31Nov 5Nov 9Nov 13Nov 17Nov 21Nov 24Nov 29Dec 5
28°FNov 14Nov 20Nov 24Nov 29Dec 1Dec 6Dec 11Dec 17Dec 29
24°FNov 25Dec 1Dec 5Dec 11Dec 18Dec 24Dec 31Jan 8Jan 24
20°FDec 2Dec 11Dec 19Dec 26Dec 31Jan 3Jan 13Jan 25Feb 11
16°FDec 7Dec 15Dec 21Dec 29Jan 1Jan 3Jan 10Jan 17Jan 30

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°F217208202197192187181175165
32°F260250242235229223216210199
28°F316303295289281272265256245
24°F365352343335328319311302288
20°F365365365365365361351337321
16°F365365365365365365365365364

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
88% of years
20°F or colder
44% of years
16°F or colder
14% 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
3,283
Cooling degree days, base 65°F
1,015
Growing degree days, base 40°F
6,888
Growing degree days, base 45°F
5,220
Growing degree days, base 50°F
3,806
Growing degree days, base 55°F
2,664
Growing degree days, base 60°F
1,743

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January609012
February503027
March445086
April3222154
May15742353
June28145567
July1322786
August1295760
September18174606
October14835355
November425091
December626011

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 17.9 km from Bangor. 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 USC00042456 (Dobbins 1 S). Public domain.