Charles Mix County climate

Charles Mix County Frost Dates and Growing Season

NOAA 1991-2020 normals for Pickstown, 16.1 km from Charles Mix County, elevation 1490 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Pickstown. 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 30 and the first fall freeze around October 13, a growing season of about 165 days.

Median at 36°F
last May 8, first October 3
Median at 32°F
last April 30, first October 13
Median at 28°F
last April 20, first October 22

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 22May 17May 14May 11May 8May 6May 3May 1Apr 28
32°FMay 12May 7May 5May 2Apr 30Apr 28Apr 25Apr 22Apr 17
28°FMay 3Apr 29Apr 26Apr 23Apr 20Apr 17Apr 14Apr 10Apr 6
24°FApr 23Apr 20Apr 16Apr 13Apr 10Apr 8Apr 4Apr 1Mar 25
20°FApr 17Apr 11Apr 8Apr 4Apr 1Mar 29Mar 25Mar 20Mar 14
16°FApr 9Apr 3Mar 31Mar 27Mar 23Mar 19Mar 14Mar 11Mar 5

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 21Sep 26Sep 28Oct 1Oct 3Oct 5Oct 9Oct 12Oct 15
32°FSep 29Oct 4Oct 7Oct 10Oct 13Oct 15Oct 18Oct 21Oct 25
28°FOct 7Oct 13Oct 17Oct 20Oct 22Oct 25Oct 27Oct 30Nov 4
24°FOct 19Oct 23Oct 26Oct 28Oct 31Nov 2Nov 5Nov 9Nov 15
20°FOct 26Oct 30Nov 1Nov 5Nov 8Nov 11Nov 14Nov 18Nov 24
16°FNov 1Nov 6Nov 10Nov 13Nov 16Nov 20Nov 23Nov 27Dec 2

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°F163158155151148144141135129
32°F183176172168165161157153148
28°F203197192188184180176172166
24°F226219213209204201196191183
20°F243235230226221217212207201
16°F262253247241237233228223215

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
6,744
Cooling degree days, base 65°F
950
Growing degree days, base 40°F
5,238
Growing degree days, base 45°F
4,127
Growing degree days, base 50°F
3,142
Growing degree days, base 55°F
2,281
Growing degree days, base 60°F
1,550

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,33400
February1,09602
March898123
April538484
May23039296
June36178593
July4334795
August9278733
September105108458
October4449139
November836020
December1,21401

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 16.1 km from Charles Mix 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 USC00396574 (Pickstown). Public domain.