Pottsville climate

Pottsville Frost Dates and Growing Season

NOAA 1991-2020 normals for Russellville Muni AP, 4.3 km from Pottsville, elevation 403 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Russellville Muni AP. 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 March 29 and the first fall freeze around November 2, a growing season of about 219 days.

Median at 36°F
last April 10, first October 25
Median at 32°F
last March 29, first November 2
Median at 28°F
last March 13, first November 14

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 24Apr 19Apr 15Apr 13Apr 10Apr 8Apr 5Mar 31Mar 26
32°FApr 13Apr 8Apr 5Apr 2Mar 29Mar 26Mar 21Mar 16Mar 10
28°FApr 4Mar 27Mar 22Mar 18Mar 13Mar 10Mar 5Mar 1Feb 25
24°FMar 18Mar 12Mar 7Mar 3Feb 28Feb 25Feb 22Feb 17Feb 7
20°FMar 7Feb 28Feb 24Feb 18Feb 14Feb 8Feb 2Jan 27Jan 18
16°FFeb 21Feb 13Feb 6Feb 1Jan 28Jan 22Jan 15Jan 5Dec 29

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

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°F217209204200196193188183176
32°F243235229224219215209204196
28°F270263256250244240235228218
24°F299289282277272266261255246
20°F335326317311304298290282272
16°F365359351344336330323312302

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
86% 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
3,279
Cooling degree days, base 65°F
1,988
Growing degree days, base 40°F
8,103
Growing degree days, base 45°F
6,578
Growing degree days, base 50°F
5,204
Growing degree days, base 55°F
3,983
Growing degree days, base 60°F
2,908

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January776124
February589147
March39812155
April16444340
May33177609
June0387837
July0521986
August0501966
September12271709
October15767384
November4416116
December710032

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 Pottsville. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USW00053920 (Russellville Muni AP). Public domain.