Mount Pleasant climate

Mount Pleasant Frost Dates and Growing Season

NOAA 1991-2020 normals for Mt Pleasant 1N, 2.6 km from Mount Pleasant, elevation 778 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mt Pleasant 1N. 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 5 and the first fall freeze around October 28, a growing season of about 204 days.

Median at 36°F
last April 15, first October 20
Median at 32°F
last April 5, first October 28
Median at 28°F
last March 25, first November 6

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

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°F206199193188183179174170163
32°F227219213208204199195189181
28°F252243237231226221215209201
24°F280269262255250245239232221
20°F311299292285278270264257249
16°F342329321312306298291282269

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
98% 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
3,739
Cooling degree days, base 65°F
1,730
Growing degree days, base 40°F
7,583
Growing degree days, base 45°F
6,115
Growing degree days, base 50°F
4,789
Growing degree days, base 55°F
3,619
Growing degree days, base 60°F
2,602

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January862024
February651142
March4767124
April21045307
May52180596
June1366814
July0460925
August0403868
September22216643
October21647320
November491391
December758135

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 2.6 km from Mount Pleasant. 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 USC00406340 (Mt Pleasant 1N). Public domain.