Centre County climate

Centre County Frost Dates and Growing Season

NOAA 1991-2020 normals for State College, 14.5 km from Centre County, elevation 1170 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for State College. 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 20 and the first fall freeze around October 26, a growing season of about 187 days.

Median at 36°F
last May 1, first October 14
Median at 32°F
last April 20, first October 26
Median at 28°F
last April 8, first November 5

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 18May 12May 8May 4May 1Apr 28Apr 25Apr 21Apr 18
32°FMay 6May 1Apr 27Apr 23Apr 20Apr 18Apr 15Apr 12Apr 7
28°FApr 23Apr 18Apr 15Apr 11Apr 8Apr 5Apr 3Mar 31Mar 26
24°FApr 9Apr 6Apr 2Mar 31Mar 30Mar 26Mar 23Mar 19Mar 14
20°FApr 1Mar 30Mar 25Mar 22Mar 19Mar 16Mar 13Mar 9Mar 5
16°FMar 24Mar 20Mar 17Mar 14Mar 11Mar 7Mar 4Feb 28Feb 22

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

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°F185178173169165161156150142
32°F207201196191187183178173165
28°F230223218214211206203197190
24°F256249243238234230225221215
20°F282273267261257253249243234
16°F304296290286280275271264257

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
6,049
Cooling degree days, base 65°F
666
Growing degree days, base 40°F
5,048
Growing degree days, base 45°F
3,890
Growing degree days, base 50°F
2,874
Growing degree days, base 55°F
1,994
Growing degree days, base 60°F
1,254

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,17202
February1,00401
March870018
April4776107
May20344317
June41136545
July5228688
August12181634
September11763399
October4168134
November716023
December1,01704

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 14.5 km from Centre 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 USC00368449 (State College). Public domain.