Richlands climate

Richlands Frost Dates and Growing Season

NOAA 1991-2020 normals for Richlands, 4.3 km from Richlands, elevation 20 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Richlands. 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 5 and the first fall freeze around November 4, a growing season of about 214 days.

Median at 36°F
last April 15, first October 28
Median at 32°F
last April 5, first November 4
Median at 28°F
last March 24, first November 16

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 30Apr 24Apr 21Apr 18Apr 15Apr 12Apr 9Apr 5Mar 31
32°FApr 20Apr 14Apr 10Apr 7Apr 5Apr 1Mar 29Mar 25Mar 19
28°FApr 9Apr 4Apr 1Mar 28Mar 24Mar 20Mar 15Mar 10Mar 2
24°FMar 31Mar 22Mar 17Mar 12Mar 8Mar 4Feb 28Feb 21Feb 8
20°FMar 13Mar 6Mar 1Feb 26Feb 20Feb 11Feb 4Jan 29Jan 16
16°FFeb 28Feb 19Feb 8Feb 2Jan 31Jan 25Jan 18Jan 11Jan 2

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 16Oct 20Oct 23Oct 26Oct 28Oct 31Nov 1Nov 4Nov 8
32°FOct 24Oct 29Nov 1Nov 2Nov 4Nov 6Nov 9Nov 12Nov 18
28°FNov 2Nov 6Nov 9Nov 12Nov 16Nov 19Nov 22Nov 27Dec 2
24°FNov 11Nov 17Nov 21Nov 25Nov 29Dec 2Dec 7Dec 16Dec 28
20°FNov 24Dec 2Dec 8Dec 15Dec 24Dec 30Jan 4Jan 10Jan 21
16°FDec 10Dec 20Dec 29Jan 3Jan 7Jan 13Jan 17Jan 24Feb 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°F213207201197194190186182175
32°F236228222217214210205200194
28°F266257250243238233228223214
24°F303291282276270264257249241
20°F339327317310304297290281272
16°F365365353344335331323313302

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
98% of years
16°F or colder
81% 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
3,077
Cooling degree days, base 65°F
1,626
Growing degree days, base 40°F
7,887
Growing degree days, base 45°F
6,316
Growing degree days, base 50°F
4,901
Growing degree days, base 55°F
3,643
Growing degree days, base 60°F
2,548

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January685050
February561263
March4269146
April20036303
May50143558
June2319766
July0426891
August0388852
September10230670
October14664392
November4027136
December596273

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 4.3 km from Richlands. 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 USC00316422 (Richlands). Public domain.