Piscataquis County climate

Piscataquis County Frost Dates and Growing Season

NOAA 1991-2020 normals for Moosehead, 43.8 km from Piscataquis County, elevation 1037 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Moosehead. 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 13 and the first fall freeze around September 30, a growing season of about 137 days.

Median at 36°F
last May 28, first September 18
Median at 32°F
last May 13, first September 30
Median at 28°F
last May 1, first October 8

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 10Jun 5Jun 3May 31May 28May 25May 22May 19May 15
32°FMay 29May 23May 19May 15May 13May 10May 8May 5May 2
28°FMay 13May 8May 5May 3May 1Apr 30Apr 29Apr 25Apr 21
24°FMay 2Apr 30Apr 28Apr 25Apr 23Apr 21Apr 18Apr 15Apr 11
20°FApr 26Apr 22Apr 20Apr 17Apr 15Apr 13Apr 10Apr 7Apr 4
16°FApr 19Apr 15Apr 12Apr 9Apr 7Apr 5Apr 3Apr 2Mar 30

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 3Sep 8Sep 12Sep 15Sep 18Sep 21Sep 25Sep 28Oct 1
32°FSep 16Sep 20Sep 24Sep 27Sep 30Oct 1Oct 3Oct 6Oct 9
28°FSep 27Oct 1Oct 3Oct 6Oct 8Oct 10Oct 13Oct 16Oct 21
24°FOct 7Oct 12Oct 15Oct 18Oct 21Oct 23Oct 27Oct 30Nov 3
20°FOct 19Oct 24Oct 28Oct 31Nov 2Nov 4Nov 7Nov 11Nov 15
16°FNov 1Nov 5Nov 8Nov 11Nov 13Nov 16Nov 18Nov 21Nov 25

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°F1301241191151111081049993
32°F152148145141137134130125119
28°F174168164161158155152148143
24°F198191187184180177173169164
20°F217211207204200197193188182
16°F233228223220217214211207202

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
9,200
Cooling degree days, base 65°F
149
Growing degree days, base 40°F
3,192
Growing degree days, base 45°F
2,302
Growing degree days, base 50°F
1,542
Growing degree days, base 55°F
918
Growing degree days, base 60°F
439

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,61200
February1,42100
March1,27402
April83305
May4454104
June17828305
July5767476
August8635414
September28514209
October657027
November97802
December1,37600

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 43.8 km from Piscataquis County. 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 USC00175460 (Moosehead). Public domain.