Trevorton climate

Trevorton Frost Dates and Growing Season

NOAA 1991-2020 normals for Sunbury, 12.7 km from Trevorton, elevation 575 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Sunbury. 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 30 and the first fall freeze around October 13, a growing season of about 166 days.

Median at 36°F
last May 11, first October 1
Median at 32°F
last April 30, first October 13
Median at 28°F
last April 14, first October 26

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 26May 22May 19May 15May 11May 7May 3Apr 29Apr 24
32°FMay 19May 12May 7May 2Apr 30Apr 26Apr 22Apr 19Apr 15
28°FMay 4Apr 26Apr 21Apr 17Apr 14Apr 12Apr 9Apr 5Mar 31
24°FApr 15Apr 10Apr 6Apr 4Apr 2Mar 31Mar 28Mar 24Mar 19
20°FApr 4Mar 31Mar 29Mar 26Mar 23Mar 20Mar 17Mar 14Mar 9
16°FMar 27Mar 23Mar 19Mar 17Mar 14Mar 11Mar 7Mar 4Feb 27

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 20Sep 24Sep 27Sep 30Oct 1Oct 4Oct 6Oct 10Oct 15
32°FSep 30Oct 3Oct 6Oct 10Oct 13Oct 16Oct 20Oct 24Oct 31
28°FOct 10Oct 15Oct 19Oct 23Oct 26Oct 30Nov 2Nov 5Nov 10
24°FOct 23Oct 29Nov 1Nov 4Nov 7Nov 10Nov 13Nov 17Nov 21
20°FNov 5Nov 11Nov 15Nov 18Nov 20Nov 22Nov 27Dec 1Dec 7
16°FNov 18Nov 22Nov 27Dec 1Dec 3Dec 7Dec 13Dec 18Dec 25

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°F165157152147143139135130123
32°F188180175171166162157152143
28°F214207202197193189184178171
24°F238231226221217213209204197
20°F263255250246242238234229222
16°F291283277271267261256251244

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
6,006
Cooling degree days, base 65°F
669
Growing degree days, base 40°F
5,024
Growing degree days, base 45°F
3,872
Growing degree days, base 50°F
2,859
Growing degree days, base 55°F
1,982
Growing degree days, base 60°F
1,249

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,17501
February98602
March851017
April480598
May20633304
June38137549
July8236693
August12188642
September12064397
October4107136
November711019
December1,01202

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 12.7 km from Trevorton. 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 USC00368668 (Sunbury). Public domain.