Callaway climate

Callaway Frost Dates and Growing Season

NOAA 1991-2020 normals for Callaway 8WSW, 13.5 km from Callaway, elevation 2913 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Callaway 8WSW. 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 3 and the first fall freeze around October 6, a growing season of about 156 days.

Median at 36°F
last May 11, first September 28
Median at 32°F
last May 3, first October 6
Median at 28°F
last April 22, first October 16

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 20May 17May 14May 11May 9May 7May 4Apr 30
32°FMay 14May 10May 7May 5May 3Apr 30Apr 28Apr 24Apr 20
28°FMay 5May 1Apr 29Apr 25Apr 22Apr 20Apr 17Apr 15Apr 10
24°FApr 27Apr 22Apr 19Apr 16Apr 13Apr 9Apr 6Apr 3Mar 28
20°FApr 19Apr 14Apr 10Apr 6Apr 3Mar 31Mar 27Mar 22Mar 16
16°FApr 10Apr 5Mar 31Mar 28Mar 23Mar 20Mar 15Mar 11Mar 5

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 20Sep 23Sep 26Sep 28Sep 30Oct 2Oct 5Oct 10
32°FSep 23Sep 28Oct 1Oct 3Oct 6Oct 9Oct 12Oct 15Oct 18
28°FSep 30Oct 5Oct 10Oct 13Oct 16Oct 19Oct 21Oct 24Oct 27
24°FOct 11Oct 16Oct 20Oct 22Oct 24Oct 27Oct 30Nov 1Nov 5
20°FOct 20Oct 24Oct 28Oct 31Nov 1Nov 5Nov 8Nov 11Nov 16
16°FOct 27Nov 1Nov 3Nov 7Nov 10Nov 14Nov 17Nov 21Nov 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°F154149145141138134131126121
32°F174167163159156152148144138
28°F194188183178175170166161153
24°F215208203198194190185179172
20°F235227222217214209205200193
16°F255247240236230226220215207

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
6,464
Cooling degree days, base 65°F
816
Growing degree days, base 40°F
5,123
Growing degree days, base 45°F
3,995
Growing degree days, base 50°F
3,005
Growing degree days, base 55°F
2,151
Growing degree days, base 60°F
1,421

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,23000
February1,01904
March830126
April529387
May24737293
June34156571
July5282742
August10239694
September11593437
October4636132
November819019
December1,16301

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 13.5 km from Callaway. 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 USC00251408 (Callaway 8WSW). Public domain.