Brimfield climate

Brimfield Frost Dates and Growing Season

NOAA 1991-2020 normals for E Brimfield Lake, 6.3 km from Brimfield, elevation 700 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for E Brimfield Lake. 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 28 and the first fall freeze around October 15, a growing season of about 169 days.

Median at 36°F
last May 11, first October 4
Median at 32°F
last April 28, first October 15
Median at 28°F
last April 13, 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 26May 21May 17May 13May 11May 7May 4May 1Apr 28
32°FMay 17May 9May 4May 1Apr 28Apr 24Apr 22Apr 19Apr 14
28°FMay 2Apr 24Apr 20Apr 17Apr 13Apr 11Apr 8Apr 6Apr 2
24°FApr 15Apr 9Apr 6Apr 4Apr 2Apr 1Mar 30Mar 25Mar 20
20°FApr 5Apr 2Mar 31Mar 28Mar 25Mar 22Mar 19Mar 16Mar 10
16°FMar 30Mar 26Mar 22Mar 19Mar 16Mar 14Mar 11Mar 7Mar 2

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 2Oct 4Oct 6Oct 10Oct 14Oct 19
32°FOct 1Oct 5Oct 8Oct 12Oct 15Oct 18Oct 21Oct 26Nov 1
28°FOct 9Oct 16Oct 19Oct 23Oct 27Oct 30Nov 1Nov 5Nov 11
24°FOct 20Oct 27Oct 31Nov 2Nov 5Nov 9Nov 13Nov 17Nov 23
20°FNov 1Nov 7Nov 12Nov 16Nov 20Nov 24Nov 28Dec 1Dec 8
16°FNov 13Nov 20Nov 25Nov 29Dec 2Dec 5Dec 9Dec 14Dec 21

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°F166160155151147143140135128
32°F190182176173169165160155148
28°F215208202197194190184178170
24°F239231226222217213209204195
20°F263255248243240235230224215
16°F283275270265260256252246240

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
6,566
Cooling degree days, base 65°F
523
Growing degree days, base 40°F
4,579
Growing degree days, base 45°F
3,470
Growing degree days, base 50°F
2,517
Growing degree days, base 55°F
1,707
Growing degree days, base 60°F
1,038

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,23502
February1,07101
March94607
April566255
May27219232
June7393471
July10196651
August19155601
September13653372
October4584104
November729019
December1,05102

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 6.3 km from Brimfield. 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 USC00192107 (E Brimfield Lake). Public domain.