Luzerne County climate

Luzerne County Frost Dates and Growing Season

NOAA 1991-2020 normals for Francis E Walter Dam, 22.8 km from Luzerne County, elevation 1509 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Francis E Walter Dam. 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 May 7 and the first fall freeze around October 6, a growing season of about 153 days.

Median at 36°F
last May 20, first September 27
Median at 32°F
last May 7, first October 6
Median at 28°F
last April 24, first October 19

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°FJun 2May 30May 26May 24May 20May 17May 13May 8May 2
32°FMay 23May 18May 14May 10May 7May 3Apr 30Apr 27Apr 22
28°FMay 11May 5Apr 30Apr 28Apr 24Apr 21Apr 18Apr 14Apr 9
24°FApr 27Apr 21Apr 17Apr 13Apr 10Apr 7Apr 5Apr 2Mar 28
20°FApr 14Apr 9Apr 6Apr 3Apr 1Mar 30Mar 27Mar 22Mar 17
16°FApr 5Apr 1Mar 30Mar 26Mar 23Mar 20Mar 17Mar 13Mar 8

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 13Sep 18Sep 22Sep 24Sep 27Sep 30Oct 1Oct 4Oct 8
32°FSep 22Sep 28Oct 1Oct 3Oct 6Oct 9Oct 12Oct 16Oct 22
28°FOct 3Oct 8Oct 11Oct 15Oct 19Oct 23Oct 27Nov 1Nov 4
24°FOct 14Oct 21Oct 25Oct 29Nov 1Nov 4Nov 8Nov 12Nov 19
20°FOct 28Nov 2Nov 7Nov 11Nov 14Nov 17Nov 21Nov 25Dec 1
16°FNov 10Nov 15Nov 19Nov 22Nov 25Nov 29Dec 2Dec 6Dec 14

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°F151143138133129124120115110
32°F174166161157153148144138131
28°F198191185181176172167162154
24°F226217212207202196191186178
20°F248240236231226221217212204
16°F271262256252248243239233224

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
7,024
Cooling degree days, base 65°F
345
Growing degree days, base 40°F
4,194
Growing degree days, base 45°F
3,132
Growing degree days, base 50°F
2,209
Growing degree days, base 55°F
1,425
Growing degree days, base 60°F
794

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,28601
February1,09901
March98108
April591359
May29219223
June9465423
July28130567
August4197521
September18529305
October507287
November804012
December1,11602

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 22.8 km from Luzerne County. 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 USC00363018 (Francis E Walter Dam). Public domain.