Scranton climate

Scranton Frost Dates and Growing Season

NOAA 1991-2020 normals for Osage City, 17.2 km from Scranton, elevation 1094 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Osage City. 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 13 and the first fall freeze around October 26, a growing season of about 194 days.

Median at 36°F
last April 24, first October 15
Median at 32°F
last April 13, first October 26
Median at 28°F
last April 2, first November 3

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 7May 3Apr 30Apr 27Apr 24Apr 21Apr 18Apr 14Apr 9
32°FApr 28Apr 23Apr 20Apr 16Apr 13Apr 10Apr 6Apr 3Mar 30
28°FApr 19Apr 13Apr 8Apr 5Apr 2Mar 31Mar 28Mar 23Mar 16
24°FApr 7Apr 2Mar 31Mar 28Mar 24Mar 20Mar 16Mar 11Mar 4
20°FMar 30Mar 24Mar 19Mar 16Mar 12Mar 8Mar 4Mar 1Feb 24
16°FMar 20Mar 14Mar 9Mar 6Mar 3Feb 28Feb 25Feb 20Feb 13

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 27Oct 3Oct 9Oct 12Oct 15Oct 18Oct 20Oct 24Oct 28
32°FOct 10Oct 16Oct 20Oct 23Oct 26Oct 28Oct 31Nov 2Nov 6
28°FOct 20Oct 25Oct 29Nov 1Nov 3Nov 5Nov 8Nov 11Nov 16
24°FOct 29Nov 2Nov 5Nov 8Nov 11Nov 14Nov 18Nov 23Nov 28
20°FNov 4Nov 8Nov 13Nov 17Nov 21Nov 24Nov 28Dec 1Dec 6
16°FNov 13Nov 20Nov 25Nov 28Dec 1Dec 3Dec 7Dec 12Dec 19

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°F193186180176172168164158150
32°F214206201197194190186179172
28°F235228222218213210205201192
24°F258250244239235230225220213
20°F277269263258254249244237229
16°F298289282277272268263258250

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
5,184
Cooling degree days, base 65°F
1,316
Growing degree days, base 40°F
6,337
Growing degree days, base 45°F
5,061
Growing degree days, base 50°F
3,920
Growing degree days, base 55°F
2,920
Growing degree days, base 60°F
2,052

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,11101
February89208
March660364
April35012184
May12897442
June7263706
July1414879
August2348810
September64152539
October29327242
November660143
December1,01802

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 17.2 km from Scranton. 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 USC00146076 (Osage City). Public domain.