Dade County climate

Dade County Frost Dates and Growing Season

NOAA 1991-2020 normals for Chickamauga 2 Sw, 17.3 km from Dade County, elevation 799 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Chickamauga 2 Sw. 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 25 and the first fall freeze around November 9, a growing season of about 232 days.

Median at 36°F
last April 7, first October 30
Median at 32°F
last March 25, first November 9
Median at 28°F
last March 11, first November 25

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 23Apr 17Apr 13Apr 10Apr 7Apr 3Apr 1Mar 28Mar 20
32°FApr 11Apr 5Apr 1Mar 29Mar 25Mar 21Mar 17Mar 13Mar 4
28°FMar 31Mar 24Mar 18Mar 15Mar 11Mar 6Feb 28Feb 25Feb 17
24°FMar 16Mar 10Mar 2Feb 27Feb 21Feb 15Feb 10Feb 3Jan 27
20°FMar 6Feb 23Feb 14Feb 8Feb 3Jan 31Jan 25Jan 17Jan 7
16°FFeb 16Feb 7Feb 1Jan 30Jan 25Jan 19Jan 14Jan 9Jan 1

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 18Oct 22Oct 25Oct 27Oct 30Nov 1Nov 3Nov 6Nov 13
32°FOct 28Nov 1Nov 3Nov 6Nov 9Nov 13Nov 17Nov 22Dec 1
28°FNov 7Nov 11Nov 16Nov 21Nov 25Dec 1Dec 3Dec 9Dec 20
24°FNov 19Nov 27Dec 2Dec 6Dec 12Dec 19Dec 26Jan 1Jan 9
20°FDec 4Dec 12Dec 23Dec 28Jan 2Jan 7Jan 13Jan 21Feb 1
16°FDec 18Dec 28Jan 1Jan 6Jan 10Jan 15Jan 21Jan 28Feb 4

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°F229221216212207203198193186
32°F259250244237232226220216207
28°F292279273265260255249242232
24°F327316308301294288280271262
20°F359345336331325319311304294
16°F365365365361352344336330319

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
93% of years
16°F or colder
66% 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
3,080
Cooling degree days, base 65°F
1,733
Growing degree days, base 40°F
7,984
Growing degree days, base 45°F
6,406
Growing degree days, base 50°F
4,986
Growing degree days, base 55°F
3,733
Growing degree days, base 60°F
2,654

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January719033
February556148
March3878157
April16642336
May42155578
June2335783
July0442907
August0425890
September9259700
October14659386
November4177123
December636144

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 17.3 km from Dade County. 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 USC00094941 (Chickamauga 2 Sw). Public domain.