Hermitage climate

Hermitage Frost Dates and Growing Season

NOAA 1991-2020 normals for Warren 2 Wsw, 18.8 km from Hermitage, elevation 210 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Warren 2 Wsw. 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 March 20 and the first fall freeze around November 11, a growing season of about 235 days.

Median at 36°F
last April 2, first October 31
Median at 32°F
last March 20, first November 11
Median at 28°F
last March 6, first November 23

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°FApr 19Apr 13Apr 9Apr 5Apr 2Mar 31Mar 26Mar 21Mar 15
32°FApr 7Apr 2Mar 29Mar 24Mar 20Mar 16Mar 12Mar 8Mar 2
28°FMar 24Mar 18Mar 14Mar 10Mar 6Mar 3Feb 28Feb 23Feb 15
24°FMar 13Mar 6Mar 2Feb 26Feb 21Feb 14Feb 8Feb 1Jan 24
20°FMar 3Feb 24Feb 15Feb 7Feb 1Jan 29Jan 22Jan 15Jan 3
16°FFeb 19Feb 9Feb 1Jan 29Jan 23Jan 18Jan 11Jan 4Dec 29

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°FOct 18Oct 23Oct 26Oct 29Oct 31Nov 2Nov 5Nov 8Nov 15
32°FOct 28Nov 1Nov 4Nov 7Nov 11Nov 14Nov 18Nov 23Nov 29
28°FNov 5Nov 10Nov 14Nov 18Nov 23Nov 27Dec 1Dec 5Dec 14
24°FNov 15Nov 23Nov 29Dec 3Dec 7Dec 13Dec 21Dec 28Jan 4
20°FDec 2Dec 10Dec 20Dec 25Dec 30Jan 2Jan 7Jan 14Jan 26
16°FDec 15Dec 26Dec 31Jan 3Jan 7Jan 12Jan 18Jan 25Feb 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°F234227221217213209204199191
32°F261252246240235231225220211
28°F290278272266261256251244234
24°F328316307299293287279271261
20°F365351341334327320311303293
16°F365365365365359350340330316

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
99% of years
20°F or colder
91% of years
16°F or colder
60% 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
2,920
Cooling degree days, base 65°F
2,014
Growing degree days, base 40°F
8,424
Growing degree days, base 45°F
6,841
Growing degree days, base 50°F
5,406
Growing degree days, base 55°F
4,116
Growing degree days, base 60°F
2,981

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January703144
February536263
March35813189
April14659372
May25191631
June1385834
July0502967
August0474939
September11293732
October13181424
November38910150
December621262

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 18.8 km from Hermitage. 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 USC00037582 (Warren 2 Wsw). Public domain.