Rich County climate

Rich County Frost Dates and Growing Season

NOAA 1991-2020 normals for Randolph, 5.7 km from Rich County, elevation 6290 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Randolph. 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 June 14 and the first fall freeze around September 1, a growing season of about 76 days.

Median at 32°F
last June 14, first September 1
Median at 28°F
last May 30, first September 11

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°F–––––––––
32°FJun 30Jun 24Jun 20Jun 17Jun 14Jun 11Jun 8Jun 4May 31
28°FJun 14Jun 9Jun 5Jun 1May 30May 26May 21May 17May 13
24°FMay 31May 25May 20May 16May 12May 9May 7May 4Apr 30
20°FMay 15May 9May 6May 3Apr 30Apr 28Apr 25Apr 20Apr 16
16°FMay 1Apr 25Apr 21Apr 17Apr 13Apr 10Apr 6Apr 2Mar 28

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°F–––––––––
32°FAug 18Aug 23Aug 26Aug 30Sep 1Sep 3Sep 5Sep 9Sep 13
28°FAug 31Sep 3Sep 6Sep 9Sep 11Sep 14Sep 16Sep 20Sep 25
24°FSep 7Sep 11Sep 15Sep 18Sep 21Sep 24Sep 27Oct 1Oct 5
20°FSep 16Sep 21Sep 25Sep 28Oct 1Oct 3Oct 7Oct 13Oct 19
16°FSep 28Oct 2Oct 6Oct 11Oct 16Oct 20Oct 23Oct 26Nov 1

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°F676055514844393428
32°F979085807672686356
28°F126119113110105100969284
24°F150144138134130126122116110
20°F175168162157154150146139132
16°F208200193188183178172166158

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
9,378
Cooling degree days, base 65°F
69
Growing degree days, base 40°F
2,727
Growing degree days, base 45°F
1,890
Growing degree days, base 50°F
1,205
Growing degree days, base 55°F
664
Growing degree days, base 60°F
274

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,52200
February1,28700
March1,07900
April79204
May546056
June2675213
July8441423
August12622364
September3751134
October749011
November1,08500
December1,46800

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 5.7 km from Rich 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 USC00427165 (Randolph). Public domain.