Marion climate

Marion Frost Dates and Growing Season

NOAA 1991-2020 normals for W Memphis, 10.2 km from Marion, elevation 215 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for W Memphis. 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 19 and the first fall freeze around November 10, a growing season of about 235 days.

Median at 36°F
last April 2, first October 31
Median at 32°F
last March 19, first November 10
Median at 28°F
last March 7, 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 20Apr 13Apr 9Apr 5Apr 2Mar 29Mar 25Mar 21Mar 14
32°FApr 7Apr 2Mar 28Mar 24Mar 19Mar 15Mar 11Mar 6Mar 1
28°FMar 31Mar 23Mar 16Mar 11Mar 7Mar 3Feb 28Feb 23Feb 16
24°FMar 18Mar 11Mar 6Mar 2Feb 27Feb 21Feb 16Feb 9Jan 31
20°FMar 9Mar 2Feb 25Feb 18Feb 11Feb 3Jan 30Jan 23Jan 11
16°FMar 1Feb 18Feb 8Feb 1Jan 29Jan 23Jan 18Jan 12Jan 2

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

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°F237228222217212208204198190
32°F262254247241235230224217210
28°F290279272265260254249243233
24°F317306300294288281274266255
20°F351338330323315308302295283
16°F365365359349342334327318306

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
95% of years
16°F or colder
75% 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
3,210
Cooling degree days, base 65°F
2,092
Growing degree days, base 40°F
8,310
Growing degree days, base 45°F
6,776
Growing degree days, base 50°F
5,384
Growing degree days, base 55°F
4,136
Growing degree days, base 60°F
3,040

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January781026
February593147
March4069160
April15957362
May30210645
June1414864
July0516981
August0487952
September11303742
October13985420
November41010144
December681142

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 10.2 km from Marion. 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 USC00037712 (W Memphis). Public domain.