Columbus climate

Columbus Frost Dates and Growing Season

NOAA 1991-2020 normals for Columbus, 1.5 km from Columbus, elevation 3602 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 May 27 and the first fall freeze around September 14, a growing season of about 108 days.

Median at 36°F
last June 12, first September 2
Median at 32°F
last May 27, first September 14
Median at 28°F
last May 13, first September 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°FJul 3Jun 24Jun 20Jun 16Jun 12Jun 9Jun 5Jun 1May 27
32°FJun 12Jun 5Jun 1May 30May 27May 25May 22May 18May 14
28°FMay 27May 23May 19May 16May 13May 11May 8May 5Apr 30
24°FMay 14May 9May 6May 4May 1Apr 29Apr 27Apr 23Apr 19
20°FMay 5Apr 30Apr 27Apr 24Apr 21Apr 17Apr 14Apr 11Apr 4
16°FApr 26Apr 19Apr 15Apr 10Apr 6Apr 3Mar 31Mar 26Mar 20

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

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°F999287837975706557
32°F128121117112108104999587
28°F153146142138134129126120115
24°F176169164160156153148144136
20°F200192187183178173169163157
16°F225217211205200195190185176

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
7,736
Cooling degree days, base 65°F
241
Growing degree days, base 40°F
3,632
Growing degree days, base 45°F
2,623
Growing degree days, base 50°F
1,788
Growing degree days, base 55°F
1,114
Growing degree days, base 60°F
591

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,29000
February1,07401
March91303
April657021
May4052130
June16224317
July34118548
August5987494
September25910227
October629045
November97203
December1,28200

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 1.5 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 USC00241938 (Columbus). Public domain.