Stowe climate

Stowe Frost Dates and Growing Season

NOAA 1991-2020 normals for Mt Mansfield, 12.3 km from Stowe, elevation 3950 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mt Mansfield. 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 23 and the first fall freeze around September 30, a growing season of about 130 days.

Median at 36°F
last June 2, first September 21
Median at 32°F
last May 23, first September 30
Median at 28°F
last May 11, 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 19Jun 12Jun 8Jun 4Jun 2May 30May 26May 23May 17
32°FJun 8Jun 2May 29May 26May 23May 19May 15May 11May 5
28°FMay 29May 22May 18May 14May 11May 7May 4Apr 30Apr 27
24°FMay 18May 12May 7May 4May 1Apr 29Apr 26Apr 22Apr 19
20°FMay 8May 3Apr 30Apr 27Apr 23Apr 21Apr 18Apr 14Apr 10
16°FApr 28Apr 23Apr 20Apr 17Apr 15Apr 12Apr 9Apr 6Apr 3

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 15Sep 18Sep 21Sep 24Sep 26Sep 29Oct 3
32°FSep 16Sep 21Sep 25Sep 28Sep 30Oct 2Oct 4Oct 7Oct 12
28°FSep 27Oct 1Oct 3Oct 6Oct 9Oct 11Oct 15Oct 18Oct 22
24°FOct 5Oct 9Oct 13Oct 16Oct 19Oct 21Oct 25Oct 29Nov 2
20°FOct 15Oct 19Oct 22Oct 26Oct 29Nov 1Nov 3Nov 6Nov 11
16°FOct 23Oct 29Nov 1Nov 3Nov 6Nov 9Nov 12Nov 16Nov 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°F1311241191141101061019689
32°F150143139135130126123116109
28°F169162158153150146141136128
24°F187181177173169164160155148
20°F207200195191187184178173165
16°F226219215210205201198193186

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
9,735
Cooling degree days, base 65°F
88
Growing degree days, base 40°F
2,863
Growing degree days, base 45°F
2,019
Growing degree days, base 50°F
1,296
Growing degree days, base 55°F
714
Growing degree days, base 60°F
306

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,60000
February1,40000
March1,30502
April899012
May5034105
June23418250
July12437379
August14922340
September3328175
October732031
November1,05603
December1,40300

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 12.3 km from Stowe. 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 USC00435416 (Mt Mansfield). Public domain.