Monroe County climate

Monroe County Frost Dates and Growing Season

NOAA 1991-2020 normals for Summer Shade, 19.4 km from Monroe County, elevation 864 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Summer Shade. 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 26 and the first fall freeze around October 18, a growing season of about 174 days.

Median at 36°F
last May 6, first October 9
Median at 32°F
last April 26, first October 18
Median at 28°F
last April 12, first October 27

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 23May 17May 13May 9May 6May 3Apr 30Apr 25Apr 20
32°FMay 16May 8May 3Apr 30Apr 26Apr 22Apr 18Apr 14Apr 7
28°FMay 5Apr 29Apr 22Apr 17Apr 12Apr 7Apr 4Mar 31Mar 26
24°FApr 24Apr 13Apr 6Apr 2Mar 31Mar 28Mar 24Mar 19Mar 13
20°FApr 7Mar 31Mar 27Mar 22Mar 19Mar 14Mar 10Mar 4Feb 25
16°FMar 27Mar 19Mar 14Mar 10Mar 5Feb 28Feb 24Feb 18Feb 11

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 26Sep 30Oct 3Oct 6Oct 9Oct 11Oct 14Oct 17Oct 21
32°FOct 5Oct 9Oct 13Oct 16Oct 18Oct 21Oct 23Oct 26Oct 29
28°FOct 14Oct 18Oct 22Oct 24Oct 27Oct 29Nov 1Nov 3Nov 8
24°FOct 23Oct 28Oct 31Nov 2Nov 5Nov 7Nov 11Nov 15Nov 21
20°FNov 1Nov 5Nov 8Nov 11Nov 15Nov 19Nov 23Nov 28Dec 5
16°FNov 9Nov 15Nov 19Nov 25Nov 30Dec 3Dec 8Dec 13Dec 22

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°F174168163159155151148143136
32°F197189183179174170165159152
28°F218211205201197191186179170
24°F244234228223218213208201191
20°F269261253247242237231224216
16°F300288280273267261254247238

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
4,128
Cooling degree days, base 65°F
1,215
Growing degree days, base 40°F
6,768
Growing degree days, base 45°F
5,364
Growing degree days, base 50°F
4,103
Growing degree days, base 55°F
2,988
Growing degree days, base 60°F
2,022

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January905015
February699127
March548495
April25631264
May8198483
June9243684
July0347812
August1310773
September41150560
October24329280
November539288
December806021

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 19.4 km from Monroe County. 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 USC00157800 (Summer Shade). Public domain.