Marshall climate

Marshall Frost Dates and Growing Season

NOAA 1991-2020 normals for Marshall, 2.8 km from Marshall, elevation 1149 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 May 5 and the first fall freeze around October 3, a growing season of about 150 days.

Median at 36°F
last May 13, first September 25
Median at 32°F
last May 5, first October 3
Median at 28°F
last April 27, first October 13

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 28May 23May 19May 16May 13May 10May 7May 5May 1
32°FMay 18May 13May 10May 7May 5May 2Apr 30Apr 27Apr 21
28°FMay 9May 5May 2Apr 30Apr 27Apr 24Apr 21Apr 17Apr 12
24°FApr 30Apr 27Apr 23Apr 20Apr 17Apr 14Apr 10Apr 7Apr 3
20°FApr 22Apr 18Apr 14Apr 11Apr 8Apr 5Apr 2Mar 31Mar 24
16°FApr 16Apr 10Apr 7Apr 4Apr 1Mar 30Mar 26Mar 21Mar 15

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 12Sep 17Sep 21Sep 23Sep 25Sep 28Oct 1Oct 4Oct 8
32°FSep 21Sep 25Sep 28Oct 1Oct 3Oct 6Oct 9Oct 12Oct 17
28°FSep 30Oct 3Oct 7Oct 10Oct 13Oct 16Oct 19Oct 22Oct 26
24°FOct 9Oct 14Oct 18Oct 20Oct 23Oct 25Oct 28Oct 31Nov 4
20°FOct 19Oct 23Oct 26Oct 29Nov 1Nov 3Nov 5Nov 9Nov 14
16°FOct 27Oct 31Nov 2Nov 5Nov 8Nov 10Nov 14Nov 17Nov 22

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°F152147143139135132128123117
32°F168162158154150148144139133
28°F189182176172168165161156150
24°F207202197191188184180175168
20°F226219213210205202197191185
16°F242233229225221216213208200

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
7,950
Cooling degree days, base 65°F
722
Growing degree days, base 40°F
4,685
Growing degree days, base 45°F
3,669
Growing degree days, base 50°F
2,760
Growing degree days, base 55°F
1,961
Growing degree days, base 60°F
1,278

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,57900
February1,30901
March1,07409
April617263
May25541283
June42159567
July9252708
August20187632
September15173382
October5317104
November963012
December1,40000

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 2.8 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 USC00215204 (Marshall). Public domain.