McPherson County climate

McPherson County Frost Dates and Growing Season

NOAA 1991-2020 normals for Aberdeen 35 Wnw, 9.3 km from McPherson County, elevation 1957 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Aberdeen 35 Wnw. 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 10 and the first fall freeze around September 30, a growing season of about 143 days.

Median at 36°F
last May 19, first September 23
Median at 32°F
last May 10, first September 30
Median at 28°F
last May 1, first October 9

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°FJun 1May 28May 25May 22May 19May 17May 14May 11May 7
32°FMay 22May 18May 15May 12May 10May 7May 5May 2Apr 28
28°FMay 14May 9May 6May 3May 1Apr 28Apr 25Apr 21Apr 16
24°FMay 5May 1Apr 27Apr 24Apr 20Apr 18Apr 14Apr 11Apr 7
20°FApr 26Apr 20Apr 16Apr 13Apr 10Apr 8Apr 5Apr 3Mar 30
16°FApr 15Apr 10Apr 7Apr 5Apr 3Apr 1Mar 29Mar 24Mar 18

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 11Sep 16Sep 19Sep 21Sep 23Sep 25Sep 27Sep 29Oct 3
32°FSep 19Sep 23Sep 26Sep 28Sep 30Oct 2Oct 5Oct 8Oct 12
28°FSep 26Oct 1Oct 3Oct 6Oct 9Oct 12Oct 14Oct 17Oct 21
24°FOct 4Oct 8Oct 12Oct 15Oct 18Oct 20Oct 23Oct 26Oct 30
20°FOct 13Oct 18Oct 22Oct 25Oct 28Oct 30Nov 2Nov 5Nov 10
16°FOct 24Oct 29Nov 1Nov 3Nov 5Nov 8Nov 10Nov 14Nov 19

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°F141136132129125122119115108
32°F161154149146143140136132127
28°F180173168164161157153149143
24°F200194188184179175171167161
20°F219212207203198194189184177
16°F235227223220215211207203196

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
8,768
Cooling degree days, base 65°F
395
Growing degree days, base 40°F
3,953
Growing degree days, base 45°F
2,997
Growing degree days, base 50°F
2,156
Growing degree days, base 55°F
1,438
Growing degree days, base 60°F
845

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,63800
February1,38900
March1,15306
April687034
May33912190
June9261421
July18159606
August38126553
September21335290
October650254
November1,07001
December1,48000

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 9.3 km from McPherson 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 USW00054933 (Aberdeen 35 Wnw). Public domain.