Middleborough climate

Middleborough Frost Dates and Growing Season

NOAA 1991-2020 normals for Middleboro, 1.3 km from Middleborough, elevation 45 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Middleboro. 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 23 and the first fall freeze around October 16, a growing season of about 174 days.

Median at 36°F
last May 6, first October 5
Median at 32°F
last April 23, first October 16
Median at 28°F
last April 9, first October 27

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 19May 15May 11May 8May 6May 3May 1Apr 28Apr 25
32°FMay 6May 1Apr 29Apr 25Apr 23Apr 21Apr 18Apr 15Apr 12
28°FApr 21Apr 17Apr 14Apr 12Apr 9Apr 8Apr 5Apr 3Mar 31
24°FApr 11Apr 7Apr 4Apr 3Apr 1Mar 30Mar 28Mar 23Mar 17
20°FApr 4Mar 31Mar 29Mar 25Mar 22Mar 19Mar 16Mar 12Mar 7
16°FMar 28Mar 23Mar 19Mar 16Mar 14Mar 11Mar 7Mar 4Feb 27

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

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°F168162157154151148144140134
32°F192186181178174170166163155
28°F215210206202199196192188182
24°F239231227223219216212208202
20°F263256250245240236232227222
16°F287280273268264260255249240

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
6,187
Cooling degree days, base 65°F
559
Growing degree days, base 40°F
4,720
Growing degree days, base 45°F
3,574
Growing degree days, base 50°F
2,589
Growing degree days, base 55°F
1,767
Growing degree days, base 60°F
1,086

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,16100
February99700
March90108
April563249
May28113217
June6688474
July8214671
August13178631
September12759384
October4115126
November689025
December97304

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 1.3 km from Middleborough. 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 USC00194711 (Middleboro). Public domain.