Buckhead Ridge Frost Dates and Growing Season

NOAA 1991-2020 normals for Okeechobee, 3.7 km from Buckhead Ridge, elevation 18 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Okeechobee. 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 January 31 and the first fall freeze around January 11, a growing season of about 355 days.

Median at 36°F: last February 7, first January 3
Median at 32°F: last January 31, first January 11
Median at 28°F: last January 22, first January 13

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 8	Mar 1	Feb 22	Feb 15	Feb 7	Feb 1	Jan 25	Jan 15	Jan 6
32°F	Mar 1	Feb 20	Feb 10	Feb 4	Jan 31	Jan 21	Jan 14	Jan 9	Jan 1
28°F	Feb 21	Feb 10	Feb 2	Jan 31	Jan 22	Jan 13	Jan 9	Jan 4	Dec 31
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 6	Dec 17	Dec 25	Dec 30	Jan 3	Jan 8	Jan 14	Jan 22	Feb 4
32°F	Dec 23	Dec 30	Jan 2	Jan 6	Jan 11	Jan 16	Jan 24	Feb 1	Feb 13
28°F	Dec 29	Jan 1	Jan 5	Jan 9	Jan 13	Jan 23	Jan 31	Feb 3	Feb 14
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	364	351	341	334	327	316	307	299	288
32°F	365	365	365	365	355	345	335	327	311
28°F	365	365	365	365	365	365	365	359	337
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: 90% of years
32°F or colder: 57% of years
28°F or colder: 24% of years
24°F or colder: 4% 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: 364
Cooling degree days, base 65°F: 3,876
Growing degree days, base 40°F: 12,637
Growing degree days, base 45°F: 10,816
Growing degree days, base 50°F: 9,004
Growing degree days, base 55°F: 7,218
Growing degree days, base 60°F: 5,493

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	133	79	422
February	74	98	446
March	27	197	636
April	4	280	726
May	0	412	877
June	0	503	953
July	0	566	1,031
August	0	569	1,034
September	0	504	954
October	4	376	837
November	30	186	606
December	93	107	484

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 3.7 km from Buckhead Ridge. 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 USC00086485 (Okeechobee). Public domain.