Pittsfield climate

Pittsfield Frost Dates and Growing Season

NOAA 1991-2020 normals for Pittsfield Muni AP, 4.4 km from Pittsfield, elevation 1194 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Pittsfield Muni 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 5 and the first fall freeze around October 5, a growing season of about 152 days.

Median at 36°F
last May 19, first September 26
Median at 32°F
last May 5, first October 5
Median at 28°F
last April 23, first October 18

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 2May 28May 25May 22May 19May 16May 13May 9May 4
32°FMay 21May 17May 13May 9May 5May 2Apr 30Apr 27Apr 23
28°FMay 9May 3Apr 30Apr 26Apr 23Apr 21Apr 18Apr 14Apr 8
24°FApr 21Apr 18Apr 14Apr 11Apr 9Apr 6Apr 4Apr 2Mar 29
20°FApr 10Apr 5Apr 3Apr 1Mar 31Mar 29Mar 26Mar 22Mar 17
16°FApr 3Mar 31Mar 28Mar 25Mar 23Mar 20Mar 17Mar 14Mar 9

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 12Sep 17Sep 21Sep 23Sep 26Sep 28Oct 1Oct 3Oct 7
32°FSep 23Sep 28Oct 1Oct 3Oct 5Oct 7Oct 11Oct 15Oct 22
28°FOct 2Oct 6Oct 11Oct 14Oct 18Oct 22Oct 26Nov 1Nov 4
24°FOct 15Oct 21Oct 26Oct 30Nov 1Nov 4Nov 6Nov 11Nov 17
20°FOct 30Nov 3Nov 6Nov 10Nov 14Nov 17Nov 20Nov 24Nov 29
16°FNov 12Nov 17Nov 21Nov 24Nov 27Nov 30Dec 3Dec 6Dec 13

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°F148142137133129126121117110
32°F171165160155152148144139133
28°F199192186180177172167163155
24°F224218212208205200196190182
20°F248241235231227223218213207
16°F269261257252249245241236229

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
7,224
Cooling degree days, base 65°F
344
Growing degree days, base 40°F
4,118
Growing degree days, base 45°F
3,075
Growing degree days, base 50°F
2,169
Growing degree days, base 55°F
1,403
Growing degree days, base 60°F
787

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,33300
February1,14700
March1,01105
April617246
May30314207
June9459416
July23136578
August39102528
September19030297
October516279
November813011
December1,14101

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 4.4 km from Pittsfield. 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 USW00014763 (Pittsfield Muni AP). Public domain.