Granville climate

Granville Frost Dates and Growing Season

NOAA 1991-2020 normals for Westfield 3 Sw, 5.6 km from Granville, elevation 430 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Westfield 3 Sw. 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 28 and the first fall freeze around October 17, a growing season of about 171 days.

Median at 36°F
last May 9, first October 5
Median at 32°F
last April 28, first October 17
Median at 28°F
last April 15, first October 30

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 22May 18May 15May 12May 9May 6May 3Apr 30Apr 26
32°FMay 11May 6May 3Apr 30Apr 28Apr 25Apr 22Apr 19Apr 15
28°FApr 30Apr 24Apr 20Apr 17Apr 15Apr 12Apr 9Apr 6Apr 2
24°FApr 15Apr 10Apr 7Apr 5Apr 3Apr 1Mar 31Mar 27Mar 21
20°FApr 4Apr 1Mar 31Mar 29Mar 26Mar 22Mar 20Mar 16Mar 11
16°FMar 30Mar 26Mar 22Mar 20Mar 17Mar 14Mar 11Mar 7Mar 3

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 24Sep 29Oct 1Oct 3Oct 5Oct 8Oct 10Oct 13Oct 18
32°FOct 2Oct 7Oct 11Oct 14Oct 17Oct 20Oct 23Oct 26Oct 31
28°FOct 16Oct 21Oct 25Oct 27Oct 30Nov 1Nov 4Nov 6Nov 10
24°FOct 30Nov 2Nov 5Nov 7Nov 9Nov 12Nov 15Nov 19Nov 25
20°FNov 7Nov 11Nov 14Nov 17Nov 20Nov 23Nov 26Dec 1Dec 5
16°FNov 14Nov 19Nov 24Nov 27Dec 1Dec 3Dec 6Dec 10Dec 17

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°F166161156153150146141137132
32°F192184180175171167163159152
28°F214209204201198194190185178
24°F237231226222219215212208202
20°F260253247243239235230226219
16°F281273267262258253250244238

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
6,519
Cooling degree days, base 65°F
612
Growing degree days, base 40°F
4,761
Growing degree days, base 45°F
3,661
Growing degree days, base 50°F
2,704
Growing degree days, base 55°F
1,872
Growing degree days, base 60°F
1,173

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,25200
February1,06801
March935010
April558363
May23925271
June49109511
July5230690
August10179634
September11864398
October4383112
November753015
December1,09401

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 5.6 km from Granville. 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 USC00199193 (Westfield 3 Sw). Public domain.