Barre climate

Barre Frost Dates and Growing Season

NOAA 1991-2020 normals for Barre Montpelier AP, 6.2 km from Barre, elevation 1126 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Barre Montpelier 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 16 and the first fall freeze around September 29, a growing season of about 136 days.

Median at 36°F
last May 30, first September 20
Median at 32°F
last May 16, first September 29
Median at 28°F
last May 3, first October 9

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 12Jun 6Jun 4Jun 1May 30May 26May 24May 20May 15
32°FMay 30May 26May 22May 19May 16May 13May 10May 6May 2
28°FMay 17May 13May 8May 5May 3Apr 30Apr 28Apr 25Apr 20
24°FMay 4Apr 30Apr 26Apr 23Apr 21Apr 18Apr 16Apr 12Apr 8
20°FApr 22Apr 18Apr 15Apr 12Apr 9Apr 7Apr 5Apr 3Mar 31
16°FApr 14Apr 9Apr 7Apr 5Apr 3Apr 1Mar 31Mar 28Mar 22

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 7Sep 11Sep 14Sep 17Sep 20Sep 23Sep 25Sep 28Oct 2
32°FSep 16Sep 21Sep 24Sep 27Sep 29Oct 1Oct 4Oct 7Oct 12
28°FSep 27Oct 1Oct 4Oct 6Oct 9Oct 12Oct 15Oct 19Oct 26
24°FOct 6Oct 10Oct 14Oct 18Oct 22Oct 25Oct 30Nov 3Nov 7
20°FOct 19Oct 25Oct 28Nov 1Nov 3Nov 6Nov 9Nov 13Nov 17
16°FNov 1Nov 4Nov 9Nov 12Nov 15Nov 18Nov 21Nov 23Nov 28

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°F13012411911611210910510195
32°F155149143140136132128123117
28°F179172167162158154150146140
24°F203197193188184180175170164
20°F224220215211207203199195187
16°F243237232228225222218214208

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
8,349
Cooling degree days, base 65°F
227
Growing degree days, base 40°F
3,596
Growing degree days, base 45°F
2,644
Growing degree days, base 50°F
1,821
Growing degree days, base 55°F
1,128
Growing degree days, base 60°F
586

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,50000
February1,29100
March1,15203
April724127
May3698157
June13641358
July4391513
August6966462
September24720245
October605150
November91807
December1,29600

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 6.2 km from Barre. 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 USW00094705 (Barre Montpelier AP). Public domain.