Saint Agatha climate

Saint Agatha Frost Dates and Growing Season

NOAA 1991-2020 normals for Frenchville Aroostook AP, 4.7 km from Saint Agatha, elevation 988 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Frenchville Aroostook 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 6 and the first fall freeze around October 2, a growing season of about 147 days.

Median at 36°F
last May 22, first September 22
Median at 32°F
last May 6, first October 2
Median at 28°F
last April 27, first October 17

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 6Jun 1May 28May 25May 22May 18May 15May 11May 6
32°FMay 21May 15May 11May 9May 6May 4May 1Apr 29Apr 25
28°FMay 7May 4May 1Apr 29Apr 27Apr 24Apr 22Apr 19Apr 13
24°FApr 29Apr 25Apr 21Apr 19Apr 17Apr 13Apr 11Apr 8Apr 5
20°FApr 22Apr 17Apr 14Apr 11Apr 8Apr 6Apr 4Apr 2Mar 30
16°FApr 15Apr 9Apr 7Apr 4Apr 3Apr 1Mar 30Mar 26Mar 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 8Sep 12Sep 15Sep 19Sep 22Sep 24Sep 27Oct 1Oct 5
32°FSep 18Sep 23Sep 26Sep 30Oct 2Oct 4Oct 8Oct 12Oct 17
28°FSep 30Oct 4Oct 9Oct 13Oct 17Oct 21Oct 24Oct 28Nov 1
24°FOct 12Oct 20Oct 25Oct 29Nov 1Nov 2Nov 5Nov 8Nov 13
20°FOct 28Nov 1Nov 4Nov 7Nov 9Nov 12Nov 15Nov 18Nov 23
16°FNov 6Nov 10Nov 13Nov 16Nov 18Nov 21Nov 24Nov 27Dec 1

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°F142135130126122117112108101
32°F165159155150147143138134128
28°F191184180176172168163159152
24°F213207203199195192188184177
20°F231225221217213210206201195
16°F245239235231228225221215210

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
9,229
Cooling degree days, base 65°F
209
Growing degree days, base 40°F
3,313
Growing degree days, base 45°F
2,426
Growing degree days, base 50°F
1,663
Growing degree days, base 55°F
1,023
Growing degree days, base 60°F
529

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,66500
February1,42800
March1,25601
April81909
May4197129
June16135327
July4985501
August7965451
September28417211
October658131
November99603
December1,41700

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 4.7 km from Saint Agatha. 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 USW00004836 (Frenchville Aroostook AP). Public domain.