Marcus climate

Marcus Frost Dates and Growing Season

NOAA 1991-2020 normals for Cherokee, 23.3 km from Marcus, elevation 1210 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Cherokee. 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 4 and the first fall freeze around October 4, a growing season of about 152 days.

Median at 36°F
last May 13, first September 25
Median at 32°F
last May 4, first October 4
Median at 28°F
last April 24, first October 15

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 25May 21May 18May 15May 13May 10May 7May 5Apr 30
32°FMay 17May 13May 9May 6May 4May 1Apr 29Apr 25Apr 20
28°FMay 7May 3Apr 30Apr 27Apr 24Apr 21Apr 18Apr 14Apr 9
24°FApr 29Apr 24Apr 20Apr 16Apr 13Apr 10Apr 7Apr 4Mar 31
20°FApr 20Apr 14Apr 10Apr 7Apr 4Apr 2Mar 31Mar 24Mar 17
16°FApr 10Apr 5Apr 1Mar 30Mar 26Mar 21Mar 17Mar 13Mar 9

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 20Sep 23Sep 25Sep 28Oct 1Oct 3Oct 7
32°FSep 20Sep 25Sep 29Oct 1Oct 4Oct 6Oct 9Oct 13Oct 18
28°FSep 30Oct 4Oct 8Oct 12Oct 15Oct 18Oct 21Oct 24Oct 28
24°FOct 12Oct 17Oct 20Oct 23Oct 25Oct 28Oct 30Nov 1Nov 5
20°FOct 20Oct 25Oct 28Oct 31Nov 1Nov 4Nov 7Nov 11Nov 16
16°FOct 29Nov 1Nov 4Nov 7Nov 10Nov 13Nov 17Nov 21Nov 27

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°F152146142138135131128123117
32°F170163158155152148144139134
28°F192185180176172168163159153
24°F212206200196192188185179172
20°F234225220215211206203198192
16°F252244239234229224220215207

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
7,404
Cooling degree days, base 65°F
755
Growing degree days, base 40°F
4,842
Growing degree days, base 45°F
3,791
Growing degree days, base 50°F
2,850
Growing degree days, base 55°F
2,028
Growing degree days, base 60°F
1,328

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,49100
February1,22101
March962016
April555580
May24146296
June37168582
July8262719
August18193640
September14674388
October4978115
November908013
December1,32200

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 23.3 km from Marcus. 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 USC00131442 (Cherokee). Public domain.