Upper Arlington climate

Upper Arlington Frost Dates and Growing Season

NOAA 1991-2020 normals for Columbus Wcmh, 4.5 km from Upper Arlington, elevation 740 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Columbus Wcmh. 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 20 and the first fall freeze around October 24, a growing season of about 185 days.

Median at 36°F
last April 30, first October 13
Median at 32°F
last April 20, first October 24
Median at 28°F
last April 8, 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 19May 12May 8May 4Apr 30Apr 28Apr 25Apr 22Apr 17
32°FMay 7May 1Apr 27Apr 24Apr 20Apr 18Apr 15Apr 11Apr 5
28°FApr 25Apr 19Apr 14Apr 11Apr 8Apr 5Apr 2Mar 31Mar 24
24°FApr 12Apr 6Apr 2Mar 31Mar 29Mar 25Mar 21Mar 17Mar 11
20°FApr 1Mar 28Mar 23Mar 20Mar 17Mar 14Mar 10Mar 6Feb 28
16°FMar 23Mar 18Mar 14Mar 10Mar 7Mar 3Feb 28Feb 23Feb 15

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 29Oct 4Oct 7Oct 10Oct 13Oct 15Oct 18Oct 21Oct 25
32°FOct 13Oct 17Oct 20Oct 22Oct 24Oct 26Oct 29Nov 1Nov 4
28°FOct 22Oct 27Oct 31Nov 1Nov 3Nov 6Nov 9Nov 12Nov 16
24°FNov 2Nov 5Nov 8Nov 11Nov 14Nov 16Nov 20Nov 25Dec 1
20°FNov 11Nov 15Nov 18Nov 23Nov 28Dec 1Dec 5Dec 9Dec 19
16°FNov 20Nov 27Dec 1Dec 5Dec 10Dec 15Dec 21Dec 25Jan 1

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°F182176172168164160156151144
32°F203197192188185181177171164
28°F229221216213209204200195189
24°F256248242236232228224218211
20°F279270263259254250245238230
16°F306296290284278272267261251

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
5,417
Cooling degree days, base 65°F
995
Growing degree days, base 40°F
5,814
Growing degree days, base 45°F
4,570
Growing degree days, base 50°F
3,471
Growing degree days, base 55°F
2,515
Growing degree days, base 60°F
1,687

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,12502
February93905
March752244
April3827152
May14878406
June12208646
July2305769
August5262722
September75116492
October34017193
November672035
December96605

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 4.5 km from Upper Arlington. 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 USC00331785 (Columbus Wcmh). Public domain.