Dunean climate

Dunean Frost Dates and Growing Season

NOAA 1991-2020 normals for Greenville, 5.1 km from Dunean, elevation 960 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Greenville. 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 28 and the first fall freeze around November 7, a growing season of about 225 days.

Median at 36°F
last April 8, first October 29
Median at 32°F
last March 28, first November 7
Median at 28°F
last March 16, first November 22

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 27Apr 20Apr 16Apr 11Apr 8Apr 6Apr 3Mar 31Mar 24
32°FApr 12Apr 6Apr 3Mar 31Mar 28Mar 25Mar 21Mar 18Mar 13
28°FApr 1Mar 27Mar 23Mar 19Mar 16Mar 13Mar 9Mar 4Feb 25
24°FMar 22Mar 16Mar 11Mar 6Feb 28Feb 24Feb 19Feb 11Jan 31
20°FMar 7Feb 28Feb 20Feb 12Feb 4Jan 31Jan 25Jan 18Jan 8
16°FFeb 21Feb 9Feb 2Jan 30Jan 24Jan 19Jan 14Jan 8Jan 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°FOct 15Oct 20Oct 23Oct 26Oct 29Nov 1Nov 3Nov 6Nov 11
32°FOct 24Oct 30Nov 2Nov 4Nov 7Nov 11Nov 14Nov 19Nov 26
28°FNov 5Nov 10Nov 14Nov 18Nov 22Nov 26Nov 30Dec 3Dec 11
24°FNov 17Nov 24Nov 29Dec 1Dec 5Dec 10Dec 18Dec 27Jan 3
20°FDec 1Dec 8Dec 15Dec 22Dec 27Jan 1Jan 5Jan 12Jan 23
16°FDec 13Dec 24Dec 29Jan 3Jan 8Jan 12Jan 17Jan 23Jan 31

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°F222215210205201197193187182
32°F247240234229225220216211205
28°F279270263257253248242236227
24°F316304295289283277271264254
20°F353342333325317310304296283
16°F365365361354346337331322310

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
97% of years
16°F or colder
72% 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
3,337
Cooling degree days, base 65°F
1,398
Growing degree days, base 40°F
7,394
Growing degree days, base 45°F
5,851
Growing degree days, base 50°F
4,479
Growing degree days, base 55°F
3,279
Growing degree days, base 60°F
2,251

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January752020
February585030
March4343123
April19229299
May51110524
June4285730
July0388852
August0363828
September16192625
October18527317
November448298
December670033

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 5.1 km from Dunean. 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 USC00383735 (Greenville). Public domain.