Marshall climate

Marshall Frost Dates and Growing Season

NOAA 1991-2020 normals for Marshall, 1.8 km from Marshall, elevation 1920 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Marshall. 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 28 and the first fall freeze around October 18, a growing season of about 173 days.

Median at 36°F
last May 7, first October 9
Median at 32°F
last April 28, first October 18
Median at 28°F
last April 14, first October 26

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 23May 16May 13May 10May 7May 5May 2Apr 30Apr 24
32°FMay 13May 9May 4Apr 30Apr 28Apr 25Apr 22Apr 17Apr 12
28°FMay 2Apr 26Apr 22Apr 17Apr 14Apr 11Apr 7Apr 3Mar 29
24°FApr 15Apr 11Apr 6Apr 3Mar 31Mar 28Mar 24Mar 20Mar 13
20°FApr 5Apr 1Mar 27Mar 23Mar 19Mar 15Mar 10Mar 4Feb 25
16°FMar 28Mar 18Mar 12Mar 7Mar 2Feb 26Feb 19Feb 12Feb 6

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 27Oct 1Oct 5Oct 7Oct 9Oct 12Oct 14Oct 18Oct 22
32°FOct 6Oct 10Oct 13Oct 15Oct 18Oct 20Oct 23Oct 27Nov 1
28°FOct 13Oct 17Oct 21Oct 24Oct 26Oct 29Nov 1Nov 4Nov 7
24°FOct 22Oct 26Oct 30Nov 1Nov 4Nov 7Nov 10Nov 13Nov 19
20°FNov 1Nov 5Nov 9Nov 13Nov 15Nov 19Nov 23Nov 28Dec 4
16°FNov 12Nov 18Nov 23Nov 27Dec 1Dec 4Dec 9Dec 18Dec 28

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°F173166162157154150146141135
32°F193186181176173169164159154
28°F214207202197194189184178172
24°F240232225220216212208203195
20°F271260252246242237232226216
16°F308295287281275268261252243

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
4,635
Cooling degree days, base 65°F
786
Growing degree days, base 40°F
5,896
Growing degree days, base 45°F
4,540
Growing degree days, base 50°F
3,358
Growing degree days, base 55°F
2,345
Growing degree days, base 60°F
1,485

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January93007
February750011
March622054
April3496167
May13943376
June19151582
July1252716
August2226688
September5397494
October30911208
November616143
December845013

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 1.8 km from Marshall. 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 USC00315356 (Marshall). Public domain.