Hendry County Frost Dates and Growing Season

NOAA 1991-2020 normals for Devils Garden, 14.4 km from Hendry County, elevation 26 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Devils Garden. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

A freeze (32°F or colder) happens in only 41 percent of years at Devils Garden, so there is no typical freeze season.

Median at 36°F: last January 30, first January 7
Median at 32°F: last January 25, first January 13
Median at 28°F: last January 20, first January 14

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.

Threshold	10%	20%	30%	40%	50%	60%	70%	80%	90%
36°F	Mar 1	Feb 17	Feb 8	Feb 2	Jan 30	Jan 26	Jan 19	Jan 12	Jan 4
32°F	Feb 13	Feb 4	Jan 31	Jan 28	Jan 25	Jan 20	Jan 14	Jan 9	Jan 1
28°F	Feb 2	Jan 29	Jan 26	Jan 23	Jan 20	Jan 15	Jan 10	Jan 7	Jan 1
24°F	–	–	–	–	–	–	–	–	–
20°F	–	–	–	–	–	–	–	–	–
16°F	–	–	–	–	–	–	–	–	–

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.

Threshold	10%	20%	30%	40%	50%	60%	70%	80%	90%
36°F	Dec 11	Dec 22	Dec 29	Jan 3	Jan 7	Jan 12	Jan 19	Jan 26	Feb 3
32°F	Dec 23	Jan 1	Jan 5	Jan 9	Jan 13	Jan 20	Jan 26	Jan 31	Feb 4
28°F	Dec 28	Jan 3	Jan 7	Jan 10	Jan 14	Jan 19	Jan 22	Jan 28	Feb 1
24°F	–	–	–	–	–	–	–	–	–
20°F	–	–	–	–	–	–	–	–	–
16°F	–	–	–	–	–	–	–	–	–

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.

Threshold	10%	20%	30%	40%	50%	60%	70%	80%	90%
36°F	365	365	354	344	337	332	325	316	305
32°F	365	365	365	365	365	365	354	339	331
28°F	365	365	365	365	365	365	365	365	357
24°F	365	365	365	365	365	365	365	365	365
20°F	365	365	365	365	365	365	365	365	365
16°F	365	365	365	365	365	365	365	365	365

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder: 80% of years
32°F or colder: 41% of years
28°F or colder: 15% of years
24°F or colder: 1% of years
20°F or colder: 0% of years
16°F or colder: 0% 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: 331
Cooling degree days, base 65°F: 3,733
Growing degree days, base 40°F: 12,527
Growing degree days, base 45°F: 10,705
Growing degree days, base 50°F: 8,891
Growing degree days, base 55°F: 7,099
Growing degree days, base 60°F: 5,364

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	122	72	424
February	62	99	458
March	35	163	595
April	6	258	702
May	1	388	853
June	0	492	942
July	0	544	1,009
August	0	560	1,025
September	0	499	950
October	2	370	832
November	23	181	608
December	81	107	496

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 14.4 km from Hendry County. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00082298 (Devils Garden). Public domain.