Point Marion climate

Point Marion Frost Dates and Growing Season

NOAA 1991-2020 normals for Lake Lynn, 4.2 km from Point Marion, elevation 900 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Lake Lynn. 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 25 and the first fall freeze around October 24, a growing season of about 181 days.

Median at 36°F
last May 6, first October 12
Median at 32°F
last April 25, first October 24
Median at 28°F
last April 11, first November 4

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 23May 17May 13May 9May 6May 2Apr 30Apr 26Apr 21
32°FMay 13May 6May 1Apr 28Apr 25Apr 21Apr 18Apr 15Apr 9
28°FApr 28Apr 21Apr 18Apr 15Apr 11Apr 7Apr 4Mar 31Mar 26
24°FApr 14Apr 9Apr 5Apr 2Mar 31Mar 27Mar 24Mar 19Mar 13
20°FApr 2Mar 29Mar 26Mar 21Mar 17Mar 14Mar 11Mar 7Mar 1
16°FMar 24Mar 18Mar 14Mar 10Mar 7Mar 5Mar 1Feb 25Feb 18

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 29Oct 4Oct 6Oct 9Oct 12Oct 14Oct 18Oct 21Oct 25
32°FOct 9Oct 14Oct 18Oct 21Oct 24Oct 27Oct 29Nov 1Nov 5
28°FOct 22Oct 26Oct 30Nov 1Nov 4Nov 6Nov 9Nov 13Nov 17
24°FNov 1Nov 5Nov 8Nov 11Nov 14Nov 16Nov 20Nov 24Nov 30
20°FNov 9Nov 14Nov 18Nov 21Nov 25Nov 29Dec 3Dec 9Dec 19
16°FNov 17Nov 24Nov 30Dec 4Dec 9Dec 15Dec 22Dec 27Jan 4

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°F177171166163159154150144137
32°F202195189185181176172166158
28°F228219214210205201196191183
24°F253245239234229225220216210
20°F281272265260253249243237230
16°F306297290285279274267259251

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
5,487
Cooling degree days, base 65°F
831
Growing degree days, base 40°F
5,522
Growing degree days, base 45°F
4,301
Growing degree days, base 50°F
3,226
Growing degree days, base 55°F
2,286
Growing degree days, base 60°F
1,486

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,08902
February93606
March764036
April4134133
May15860375
June18168600
July3276738
August4227688
September8289459
October3766158
November691129
December95202

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 4.2 km from Point Marion. 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 USC00465002 (Lake Lynn). Public domain.