McGehee climate

McGehee Frost Dates and Growing Season

NOAA 1991-2020 normals for Dermott 3 Ne, 7.8 km from McGehee, elevation 145 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Dermott 3 Ne. 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 13 and the first fall freeze around November 10, a growing season of about 242 days.

Median at 36°F
last March 26, first October 31
Median at 32°F
last March 13, first November 10
Median at 28°F
last February 28, first November 23

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 12Apr 6Apr 3Mar 30Mar 26Mar 23Mar 19Mar 14Mar 7
32°FMar 31Mar 25Mar 20Mar 17Mar 13Mar 9Mar 5Feb 28Feb 23
28°FMar 18Mar 13Mar 8Mar 3Feb 28Feb 25Feb 20Feb 13Feb 1
24°FMar 9Mar 1Feb 25Feb 19Feb 12Feb 5Jan 31Jan 25Jan 16
20°FFeb 28Feb 17Feb 9Feb 1Jan 30Jan 23Jan 16Jan 9Dec 29
16°FFeb 15Feb 6Feb 1Jan 28Jan 21Jan 15Jan 10Jan 5Dec 30

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 25Oct 28Oct 31Nov 2Nov 5Nov 8Nov 15
32°FOct 25Oct 31Nov 3Nov 6Nov 10Nov 14Nov 18Nov 23Nov 30
28°FNov 4Nov 10Nov 15Nov 19Nov 23Nov 29Dec 3Dec 7Dec 16
24°FNov 14Nov 22Nov 29Dec 5Dec 11Dec 19Dec 28Jan 3Jan 14
20°FDec 1Dec 11Dec 21Dec 29Jan 2Jan 7Jan 12Jan 21Feb 1
16°FDec 18Dec 31Jan 3Jan 7Jan 11Jan 17Jan 24Feb 1Feb 6

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°F240232226221216212208203194
32°F269260252247242237231225215
28°F301291282275269263257250240
24°F336324316309304298290278268
20°F365365354345337332323315304
16°F365365365365365365357344332

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
98% of years
20°F or colder
82% of years
16°F or colder
41% 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
2,853
Cooling degree days, base 65°F
2,149
Growing degree days, base 40°F
8,630
Growing degree days, base 45°F
7,046
Growing degree days, base 50°F
5,601
Growing degree days, base 55°F
4,300
Growing degree days, base 60°F
3,144

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January702142
February527269
March34117207
April13075403
May22230673
June0414864
July0508973
August0480945
September10309748
October12297448
November37413167
December624262

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 7.8 km from McGehee. 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 USC00031962 (Dermott 3 Ne). Public domain.