Gorham climate

Gorham Frost Dates and Growing Season

NOAA 1991-2020 normals for Gorham AP, 1.8 km from Gorham, elevation 800 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Gorham AP. 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 14 and the first fall freeze around September 26, a growing season of about 133 days.

Median at 36°F
last May 29, first September 13
Median at 32°F
last May 14, first September 26
Median at 28°F
last May 2, first October 4

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 13Jun 7Jun 4Jun 1May 29May 25May 22May 19May 15
32°FMay 29May 24May 20May 17May 14May 11May 8May 5May 2
28°FMay 14May 9May 6May 4May 2Apr 30Apr 28Apr 26Apr 22
24°FApr 30Apr 27Apr 25Apr 22Apr 20Apr 17Apr 15Apr 12Apr 8
20°FApr 20Apr 16Apr 13Apr 10Apr 8Apr 6Apr 4Apr 3Mar 31
16°FApr 10Apr 7Apr 5Apr 4Apr 2Mar 31Mar 29Mar 25Mar 20

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 1Sep 4Sep 7Sep 10Sep 13Sep 16Sep 20Sep 23Sep 27
32°FSep 11Sep 16Sep 19Sep 23Sep 26Sep 28Sep 30Oct 3Oct 6
28°FSep 22Sep 27Sep 30Oct 2Oct 4Oct 7Oct 11Oct 15Oct 21
24°FOct 2Oct 6Oct 11Oct 15Oct 19Oct 23Oct 28Nov 2Nov 7
20°FOct 17Oct 23Oct 28Nov 1Nov 4Nov 7Nov 10Nov 13Nov 18
16°FNov 1Nov 6Nov 10Nov 13Nov 16Nov 19Nov 22Nov 25Nov 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°F1271191151111071041009587
32°F149143138136133129125120113
28°F173167163159155152148143137
24°F202196191186182178174169161
20°F227219215211207203199194187
16°F246240235232228224220215209

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
8,300
Cooling degree days, base 65°F
184
Growing degree days, base 40°F
3,573
Growing degree days, base 45°F
2,600
Growing degree days, base 50°F
1,767
Growing degree days, base 55°F
1,094
Growing degree days, base 60°F
548

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,50400
February1,29200
March1,16401
April72706
May3433161
June13035360
July3186520
August5343456
September25317231
October601031
November91702
December1,28600

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 1.8 km from Gorham. 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 USC00273488 (Gorham AP). Public domain.