Greenville climate

Greenville Frost Dates and Growing Season

NOAA 1991-2020 normals for Greenville Wtp, 1.5 km from Greenville, elevation 1030 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Greenville Wtp. 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 21 and the first fall freeze around October 20, a growing season of about 180 days.

Median at 36°F
last May 1, first October 8
Median at 32°F
last April 21, first October 20
Median at 28°F
last April 9, first October 31

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 18May 12May 8May 4May 1Apr 29Apr 26Apr 23Apr 19
32°FMay 7May 1Apr 27Apr 24Apr 21Apr 19Apr 16Apr 12Apr 7
28°FApr 24Apr 19Apr 15Apr 12Apr 9Apr 6Apr 3Mar 31Mar 26
24°FApr 12Apr 6Apr 2Mar 31Mar 29Mar 25Mar 22Mar 19Mar 13
20°FApr 2Mar 30Mar 25Mar 22Mar 20Mar 16Mar 12Mar 9Mar 4
16°FMar 25Mar 20Mar 16Mar 12Mar 9Mar 6Mar 3Feb 28Feb 19

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 24Sep 29Oct 2Oct 5Oct 8Oct 10Oct 13Oct 16Oct 21
32°FOct 6Oct 11Oct 14Oct 17Oct 20Oct 22Oct 25Oct 28Nov 1
28°FOct 18Oct 23Oct 26Oct 28Oct 31Nov 1Nov 4Nov 7Nov 13
24°FOct 27Nov 1Nov 2Nov 6Nov 9Nov 12Nov 16Nov 21Nov 29
20°FNov 3Nov 8Nov 13Nov 18Nov 22Nov 26Dec 1Dec 5Dec 13
16°FNov 13Nov 20Nov 27Dec 1Dec 5Dec 9Dec 14Dec 19Dec 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°F179172166163158155150146138
32°F201194189184180176171168160
28°F224218213207203198194189183
24°F248242236231225222217212205
20°F272264258253248243238232225
16°F296287280275270265259253245

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
5,672
Cooling degree days, base 65°F
933
Growing degree days, base 40°F
5,656
Growing degree days, base 45°F
4,440
Growing degree days, base 50°F
3,360
Growing degree days, base 55°F
2,414
Growing degree days, base 60°F
1,603

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,17604
February97305
March779137
April41310143
May15677394
June21209637
July2284747
August6230688
September84106475
October35716185
November687038
December1,01706

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 1.5 km from Greenville. 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 USC00333375 (Greenville Wtp). Public domain.