Summit County climate

Summit County Frost Dates and Growing Season

NOAA 1991-2020 normals for Stow 4 Se, 7 km from Summit County, elevation 1060 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Stow 4 Se. 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 30 and the first fall freeze around October 21, a growing season of about 173 days.

Median at 36°F
last May 9, first October 8
Median at 32°F
last April 30, first October 21
Median at 28°F
last April 20, first November 2

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 25May 20May 16May 13May 9May 6May 3Apr 30Apr 26
32°FMay 16May 10May 6May 2Apr 30Apr 27Apr 24Apr 22Apr 17
28°FMay 4Apr 29Apr 26Apr 23Apr 20Apr 18Apr 15Apr 10Apr 6
24°FApr 21Apr 17Apr 15Apr 11Apr 8Apr 4Apr 2Mar 31Mar 25
20°FApr 11Apr 5Apr 3Mar 31Mar 29Mar 25Mar 22Mar 17Mar 12
16°FApr 1Mar 28Mar 24Mar 21Mar 18Mar 15Mar 11Mar 5Feb 28

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 27Oct 1Oct 4Oct 6Oct 8Oct 11Oct 14Oct 17Oct 22
32°FOct 7Oct 12Oct 15Oct 19Oct 21Oct 23Oct 27Oct 30Nov 2
28°FOct 21Oct 25Oct 29Oct 31Nov 2Nov 5Nov 8Nov 12Nov 17
24°FNov 1Nov 4Nov 7Nov 10Nov 13Nov 16Nov 20Nov 24Nov 30
20°FNov 8Nov 12Nov 16Nov 20Nov 24Nov 28Dec 1Dec 4Dec 10
16°FNov 15Nov 22Nov 27Dec 1Dec 4Dec 7Dec 12Dec 18Dec 24

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°F170163158154150146143137132
32°F191184181177173170165160153
28°F214208203199195191188183175
24°F243234228224219216212208202
20°F265257251246242237232227220
16°F287280274268264259254247239

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
6,312
Cooling degree days, base 65°F
601
Growing degree days, base 40°F
4,887
Growing degree days, base 45°F
3,748
Growing degree days, base 50°F
2,758
Growing degree days, base 55°F
1,900
Growing degree days, base 60°F
1,175

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,21301
February1,04403
March910013
April507293
May22632298
June42113523
July10206660
August15168618
September12473402
October4398126
November741019
December1,04203

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 7 km from Summit County. 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 USC00338062 (Stow 4 Se). Public domain.