Bennington climate

Bennington Frost Dates and Growing Season

NOAA 1991-2020 normals for Ft Calhoun 4W, 10.5 km from Bennington, elevation 1310 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Ft Calhoun 4W. 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 19 and the first fall freeze around October 17, a growing season of about 180 days.

Median at 36°F
last May 1, first October 7
Median at 32°F
last April 19, first October 17
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 14May 9May 6May 3May 1Apr 29Apr 25Apr 21Apr 16
32°FMay 6Apr 30Apr 27Apr 23Apr 19Apr 16Apr 13Apr 10Apr 5
28°FApr 24Apr 19Apr 15Apr 11Apr 9Apr 6Apr 3Apr 1Mar 28
24°FApr 14Apr 10Apr 6Apr 4Apr 1Mar 31Mar 27Mar 23Mar 16
20°FApr 6Apr 2Mar 30Mar 27Mar 23Mar 20Mar 16Mar 12Mar 7
16°FMar 31Mar 25Mar 21Mar 18Mar 14Mar 11Mar 8Mar 4Mar 1

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 23Sep 28Oct 1Oct 4Oct 7Oct 10Oct 13Oct 16Oct 20
32°FOct 1Oct 7Oct 11Oct 14Oct 17Oct 20Oct 23Oct 26Oct 31
28°FOct 12Oct 18Oct 21Oct 24Oct 27Oct 30Nov 1Nov 5Nov 9
24°FOct 20Oct 25Oct 30Nov 1Nov 4Nov 7Nov 9Nov 13Nov 18
20°FOct 29Nov 2Nov 6Nov 8Nov 11Nov 14Nov 18Nov 22Nov 28
16°FNov 4Nov 9Nov 12Nov 16Nov 20Nov 23Nov 27Dec 1Dec 5

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°F178171166162158154150145139
32°F198192187183180175172166158
28°F221214208203199195191185177
24°F239231226222217213209204196
20°F256248242238233229225220213
16°F273266260255251246242236228

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
6,575
Cooling degree days, base 65°F
897
Growing degree days, base 40°F
5,319
Growing degree days, base 45°F
4,193
Growing degree days, base 50°F
3,190
Growing degree days, base 55°F
2,301
Growing degree days, base 60°F
1,533

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,35400
February1,10701
March854134
April4626124
May19751336
June23189616
July4297758
August8242699
September10599448
October42411156
November827017
December1,21000

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 10.5 km from Bennington. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00252980 (Ft Calhoun 4W). Public domain.