Saline County climate

Saline County Frost Dates and Growing Season

NOAA 1991-2020 normals for Marshall, 1.8 km from Saline County, elevation 790 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 10 and the first fall freeze around October 24, a growing season of about 196 days.

Median at 36°F
last April 21, first October 15
Median at 32°F
last April 10, first October 24
Median at 28°F
last March 31, first November 3

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 5May 1Apr 28Apr 24Apr 21Apr 18Apr 15Apr 11Apr 7
32°FApr 27Apr 21Apr 17Apr 14Apr 10Apr 7Apr 4Apr 1Mar 27
28°FApr 16Apr 10Apr 6Apr 2Mar 31Mar 28Mar 23Mar 19Mar 13
24°FApr 5Mar 31Mar 27Mar 23Mar 19Mar 16Mar 13Mar 8Mar 3
20°FMar 29Mar 21Mar 17Mar 14Mar 10Mar 6Mar 3Feb 28Feb 22
16°FMar 18Mar 13Mar 9Mar 6Mar 3Feb 28Feb 24Feb 19Feb 12

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 28Oct 3Oct 8Oct 12Oct 15Oct 18Oct 20Oct 23Oct 27
32°FOct 12Oct 16Oct 19Oct 22Oct 24Oct 27Oct 30Nov 1Nov 6
28°FOct 22Oct 26Oct 30Nov 1Nov 3Nov 5Nov 8Nov 12Nov 18
24°FNov 1Nov 4Nov 7Nov 10Nov 12Nov 16Nov 20Nov 25Nov 30
20°FNov 7Nov 12Nov 16Nov 21Nov 25Nov 28Dec 1Dec 5Dec 13
16°FNov 14Nov 21Nov 27Nov 30Dec 2Dec 6Dec 11Dec 17Dec 23

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°F194187183178175171167161155
32°F217209204200196192188182175
28°F240232226221218213210205198
24°F263254249243238233229224217
20°F282274268263258253247241233
16°F301292286281275270265259251

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
5,263
Cooling degree days, base 65°F
1,280
Growing degree days, base 40°F
6,280
Growing degree days, base 45°F
5,021
Growing degree days, base 50°F
3,892
Growing degree days, base 55°F
2,894
Growing degree days, base 60°F
2,020

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,15102
February91309
March683361
April35416187
May11598453
June9270711
July1387851
August3327789
September66150536
October30829237
November657150
December1,00407

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 Saline County. 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 USW00013991 (Marshall). Public domain.