Green County climate

Green County Frost Dates and Growing Season

NOAA 1991-2020 normals for Monroe Wwtp, 10.4 km from Green County, elevation 991 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Monroe Wwtp. 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 27 and the first fall freeze around October 14, a growing season of about 170 days.

Median at 36°F
last May 6, first October 4
Median at 32°F
last April 27, first October 14
Median at 28°F
last April 15, first October 25

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 22May 17May 14May 10May 6May 4May 1Apr 28Apr 23
32°FMay 12May 6May 2Apr 30Apr 27Apr 24Apr 20Apr 16Apr 12
28°FMay 1Apr 26Apr 22Apr 18Apr 15Apr 12Apr 9Apr 6Apr 2
24°FApr 20Apr 14Apr 10Apr 7Apr 4Apr 2Mar 31Mar 27Mar 21
20°FApr 9Apr 3Apr 1Mar 30Mar 26Mar 22Mar 18Mar 15Mar 9
16°FMar 31Mar 26Mar 22Mar 19Mar 16Mar 13Mar 10Mar 7Mar 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 21Sep 26Sep 29Oct 2Oct 4Oct 7Oct 9Oct 12Oct 17
32°FSep 29Oct 4Oct 8Oct 12Oct 14Oct 17Oct 20Oct 23Oct 29
28°FOct 9Oct 15Oct 19Oct 22Oct 25Oct 27Oct 30Nov 1Nov 7
24°FOct 23Oct 28Oct 31Nov 1Nov 4Nov 7Nov 10Nov 14Nov 19
20°FNov 1Nov 5Nov 8Nov 12Nov 15Nov 18Nov 22Nov 25Nov 30
16°FNov 7Nov 13Nov 17Nov 20Nov 24Nov 26Nov 30Dec 3Dec 8

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°F168161157153149145141136130
32°F189183178174170165160156149
28°F211205199194190186182178169
24°F234227221217213209205200193
20°F255247241237233229225220213
16°F272265260255251247242236230

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
7,115
Cooling degree days, base 65°F
697
Growing degree days, base 40°F
4,815
Growing degree days, base 45°F
3,746
Growing degree days, base 50°F
2,802
Growing degree days, base 55°F
1,976
Growing degree days, base 60°F
1,266

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,43200
February1,18400
March951115
April544277
May22742301
June33162579
July8242699
August15181631
September14161378
October4796110
November852012
December1,24900

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 10.4 km from Green 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 USC00475573 (Monroe Wwtp). Public domain.