Richland County climate

Richland County Frost Dates and Growing Season

NOAA 1991-2020 normals for Lidgerwood, 26.3 km from Richland County, elevation 1125 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Lidgerwood. 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 2 and the first fall freeze around October 6, a growing season of about 157 days.

Median at 36°F
last May 12, first September 28
Median at 32°F
last May 2, first October 6
Median at 28°F
last April 23, first October 18

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 26May 21May 17May 15May 12May 9May 6May 3Apr 30
32°FMay 15May 11May 7May 4May 2Apr 30Apr 28Apr 25Apr 20
28°FMay 5May 1Apr 29Apr 26Apr 23Apr 20Apr 17Apr 13Apr 9
24°FApr 27Apr 21Apr 18Apr 15Apr 13Apr 10Apr 7Apr 4Apr 1
20°FApr 18Apr 14Apr 10Apr 7Apr 5Apr 3Mar 31Mar 27Mar 20
16°FApr 12Apr 7Apr 3Apr 1Mar 30Mar 25Mar 21Mar 17Mar 14

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

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°F157151147143140136133129123
32°F176169165161157154150146140
28°F196189185180176173169164156
24°F216209204201197193189184176
20°F231225220217213209206201194
16°F247239235231227224220215210

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
8,565
Cooling degree days, base 65°F
565
Growing degree days, base 40°F
4,318
Growing degree days, base 45°F
3,344
Growing degree days, base 50°F
2,476
Growing degree days, base 55°F
1,715
Growing degree days, base 60°F
1,076

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,68500
February1,40700
March1,16105
April668144
May29225242
June56113508
July12207660
August23162604
September17953336
October584476
November1,02802
December1,47100

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 26.3 km from Richland 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 USC00325186 (Lidgerwood). Public domain.