Columbus climate

Columbus Frost Dates and Growing Season

NOAA 1991-2020 normals for Columbus, 0.2 km from Columbus, elevation 4065 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Columbus. 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 March 18 and the first fall freeze around November 11, a growing season of about 237 days.

Median at 36°F
last April 4, first November 3
Median at 32°F
last March 18, first November 11
Median at 28°F
last February 28, first November 21

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°FApr 21Apr 15Apr 10Apr 7Apr 4Apr 1Mar 29Mar 24Mar 17
32°FApr 6Mar 31Mar 26Mar 22Mar 18Mar 14Mar 10Mar 5Feb 28
28°FMar 20Mar 12Mar 7Mar 3Feb 28Feb 23Feb 18Feb 12Feb 4
24°FMar 3Feb 24Feb 16Feb 9Feb 3Jan 30Jan 27Jan 21Jan 12
20°FFeb 15Feb 3Jan 29Jan 23Jan 17Jan 11Jan 5Dec 29Dec 20
16°FFeb 1Jan 22Jan 15Jan 9Jan 5Dec 31Dec 27Dec 20Dec 12

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°FOct 21Oct 26Oct 30Nov 1Nov 3Nov 5Nov 8Nov 11Nov 16
32°FOct 29Nov 3Nov 5Nov 8Nov 11Nov 14Nov 17Nov 20Nov 24
28°FNov 5Nov 11Nov 15Nov 18Nov 21Nov 24Nov 27Dec 1Dec 5
24°FNov 18Nov 24Nov 27Nov 30Dec 2Dec 6Dec 8Dec 13Dec 20
20°FNov 28Dec 3Dec 8Dec 13Dec 16Dec 20Dec 27Jan 1Jan 12
16°FDec 7Dec 14Dec 19Dec 25Dec 29Jan 2Jan 7Jan 14Jan 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°F233225220216212208204199193
32°F260252247241237232227221214
28°F292283277271266261256249239
24°F329320312307301294288281271
20°F365356349342336330323312302
16°F365365365365365361353346334

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
91% of years
16°F or colder
45% 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
2,414
Cooling degree days, base 65°F
2,362
Growing degree days, base 40°F
9,129
Growing degree days, base 45°F
7,441
Growing degree days, base 50°F
5,906
Growing degree days, base 55°F
4,554
Growing degree days, base 60°F
3,381

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January614024
February412070
March2587228
April8361428
May8257715
June0522972
July05641,029
August0508973
September2341789
October6199506
November3543147
December623025

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 0.2 km from Columbus. 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 USW00023058 (Columbus). Public domain.