Hermitage climate

Hermitage Frost Dates and Growing Season

NOAA 1991-2020 normals for Youngstown Rgnl AP, 19 km from Hermitage, elevation 1180 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Youngstown Rgnl 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 1 and the first fall freeze around October 17, a growing season of about 167 days.

Median at 36°F
last May 16, first October 5
Median at 32°F
last May 1, first October 17
Median at 28°F
last April 20, first November 1

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 31May 26May 22May 18May 16May 11May 7May 2Apr 27
32°FMay 20May 15May 9May 4May 1Apr 28Apr 25Apr 21Apr 16
28°FMay 7Apr 30Apr 26Apr 22Apr 20Apr 17Apr 14Apr 9Apr 5
24°FApr 21Apr 17Apr 14Apr 9Apr 6Apr 4Apr 2Mar 30Mar 24
20°FApr 10Apr 5Apr 2Mar 31Mar 28Mar 25Mar 21Mar 17Mar 11
16°FMar 31Mar 28Mar 24Mar 20Mar 18Mar 15Mar 11Mar 7Mar 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 22Sep 27Oct 1Oct 2Oct 5Oct 8Oct 11Oct 14Oct 20
32°FOct 1Oct 6Oct 10Oct 14Oct 17Oct 21Oct 24Oct 28Nov 1
28°FOct 15Oct 20Oct 25Oct 29Nov 1Nov 3Nov 6Nov 10Nov 15
24°FNov 1Nov 4Nov 6Nov 9Nov 12Nov 15Nov 19Nov 24Nov 30
20°FNov 8Nov 13Nov 17Nov 21Nov 25Nov 28Dec 1Dec 6Dec 12
16°FNov 18Nov 25Nov 29Dec 3Dec 7Dec 10Dec 15Dec 20Dec 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°F165158153148143138134128121
32°F190183178172167162157151145
28°F217209204199194190184178167
24°F241234229224220216212207200
20°F268259253247242238233228220
16°F290281276270266261255250242

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
6,090
Cooling degree days, base 65°F
633
Growing degree days, base 40°F
5,034
Growing degree days, base 45°F
3,865
Growing degree days, base 50°F
2,840
Growing degree days, base 55°F
1,954
Growing degree days, base 60°F
1,211

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,18403
February1,00804
March863129
April4847109
May22243305
June52127525
July9211666
August17170618
September11965399
October4089143
November705032
December1,02005

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 19 km from Hermitage. 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 USW00014852 (Youngstown Rgnl AP). Public domain.