Pomeroy climate

Pomeroy Frost Dates and Growing Season

NOAA 1991-2020 normals for Carpenter 2 S, 20.8 km from Pomeroy, elevation 822 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Carpenter 2 S. 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 27 and the first fall freeze around October 14, a growing season of about 168 days.

Median at 36°F
last May 7, first October 5
Median at 32°F
last April 27, first October 14
Median at 28°F
last April 13, 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 24May 18May 14May 10May 7May 3Apr 30Apr 27Apr 21
32°FMay 15May 9May 4Apr 30Apr 27Apr 23Apr 19Apr 16Apr 11
28°FMay 3Apr 25Apr 20Apr 16Apr 13Apr 9Apr 6Apr 3Mar 30
24°FApr 16Apr 9Apr 5Apr 2Mar 31Mar 29Mar 25Mar 21Mar 14
20°FApr 3Mar 31Mar 27Mar 24Mar 20Mar 17Mar 13Mar 8Mar 1
16°FMar 27Mar 21Mar 17Mar 13Mar 9Mar 5Mar 2Feb 26Feb 19

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 23Sep 28Oct 1Oct 3Oct 5Oct 8Oct 10Oct 14Oct 19
32°FOct 2Oct 6Oct 9Oct 11Oct 14Oct 18Oct 21Oct 23Oct 28
28°FOct 11Oct 16Oct 20Oct 23Oct 26Oct 28Oct 31Nov 3Nov 9
24°FOct 24Oct 29Nov 1Nov 3Nov 6Nov 9Nov 13Nov 17Nov 24
20°FNov 2Nov 6Nov 11Nov 14Nov 18Nov 22Nov 28Dec 2Dec 9
16°FNov 10Nov 17Nov 23Nov 28Dec 2Dec 6Dec 11Dec 17Dec 27

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°F170162157153150145141136129
32°F188182177173168164160155147
28°F215208203199194190184178170
24°F244236229223219215211206198
20°F273263256250245240235228220
16°F299289281275269263257249240

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
5,280
Cooling degree days, base 65°F
826
Growing degree days, base 40°F
5,681
Growing degree days, base 45°F
4,423
Growing degree days, base 50°F
3,306
Growing degree days, base 55°F
2,331
Growing degree days, base 60°F
1,503

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,06908
February90007
March720251
April38015175
May15558375
June27162585
July2252715
August6234693
September7892465
October35610178
November659146
December928010

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 20.8 km from Pomeroy. 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 USC00331288 (Carpenter 2 S). Public domain.