Columbus climate

Columbus Frost Dates and Growing Season

NOAA 1991-2020 normals for Union City Filtration Plant, 23.5 km from Columbus, elevation 1400 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Union City Filtration Plant. 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 May 7 and the first fall freeze around October 10, a growing season of about 155 days.

Median at 36°F
last May 20, first September 30
Median at 32°F
last May 7, first October 10
Median at 28°F
last April 24, first October 23

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°FJun 1May 29May 26May 23May 20May 17May 13May 10May 5
32°FMay 24May 19May 14May 11May 7May 4Apr 30Apr 27Apr 23
28°FMay 12May 6May 1Apr 27Apr 24Apr 21Apr 18Apr 14Apr 9
24°FApr 24Apr 19Apr 16Apr 12Apr 9Apr 6Apr 4Apr 1Mar 29
20°FApr 12Apr 7Apr 4Apr 2Mar 31Mar 29Mar 26Mar 22Mar 18
16°FApr 2Mar 31Mar 28Mar 25Mar 22Mar 20Mar 17Mar 14Mar 9

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 17Sep 22Sep 25Sep 28Sep 30Oct 1Oct 4Oct 7Oct 11
32°FSep 29Oct 1Oct 4Oct 6Oct 10Oct 13Oct 15Oct 18Oct 24
28°FOct 6Oct 12Oct 16Oct 20Oct 23Oct 27Oct 31Nov 4Nov 10
24°FOct 21Oct 28Nov 1Nov 4Nov 8Nov 11Nov 15Nov 19Nov 26
20°FNov 5Nov 9Nov 13Nov 17Nov 21Nov 25Nov 29Dec 2Dec 7
16°FNov 14Nov 20Nov 25Nov 29Dec 2Dec 5Dec 9Dec 13Dec 18

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°F152144139135132129125121115
32°F175168163159155151145140134
28°F204196190186181176170165157
24°F233225220215210206202197189
20°F258251245240236231227222215
16°F275268262258254250246241235

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
6,901
Cooling degree days, base 65°F
420
Growing degree days, base 40°F
4,351
Growing degree days, base 45°F
3,277
Growing degree days, base 50°F
2,350
Growing degree days, base 55°F
1,555
Growing degree days, base 60°F
906

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,26101
February1,12701
March98907
April598157
May29023245
June7574450
July24153593
August40121545
September16646337
October478498
November765015
December1,08801

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 23.5 km from Columbus. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00369042 (Union City Filtration Plant). Public domain.