Bunnell Frost Dates and Growing Season

NOAA 1991-2020 normals for Palm Coast 6NE, 19.1 km from Bunnell, elevation 5 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Palm Coast 6NE. 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 24 and the first fall freeze around January 11, a growing season of about 356 days.

Median at 36°F: last February 4, first January 3
Median at 32°F: last January 24, first January 11
Median at 28°F: last January 19, first January 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.

Threshold	10%	20%	30%	40%	50%	60%	70%	80%	90%
36°F	Mar 3	Feb 25	Feb 16	Feb 10	Feb 4	Jan 31	Jan 26	Jan 17	Jan 6
32°F	Feb 18	Feb 7	Feb 2	Jan 30	Jan 24	Jan 18	Jan 13	Jan 6	Dec 31
28°F	Feb 7	Feb 1	Jan 31	Jan 26	Jan 19	Jan 12	Jan 8	Jan 3	Dec 28
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 7	Dec 18	Dec 25	Jan 1	Jan 3	Jan 9	Jan 14	Jan 23	Feb 4
32°F	Dec 19	Dec 28	Jan 1	Jan 5	Jan 11	Jan 16	Jan 22	Jan 30	Feb 7
28°F	Dec 24	Jan 1	Jan 4	Jan 9	Jan 16	Jan 21	Jan 29	Feb 1	Feb 5
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	363	350	341	334	328	322	314	306	295
32°F	365	365	365	365	356	346	339	332	320
28°F	365	365	365	365	365	365	365	359	340
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: 88% of years
32°F or colder: 57% of years
28°F or colder: 20% 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: 792
Cooling degree days, base 65°F: 3,143
Growing degree days, base 40°F: 11,480
Growing degree days, base 45°F: 9,669
Growing degree days, base 50°F: 7,885
Growing degree days, base 55°F: 6,170
Growing degree days, base 60°F: 4,573

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	264	22	254
February	171	31	290
March	93	69	442
April	20	171	602
May	1	346	811
June	0	475	925
July	0	532	997
August	0	535	1,000
September	0	474	924
October	8	321	778
November	58	120	512
December	178	48	351

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 19.1 km from Bunnell. 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 USC00086767 (Palm Coast 6NE). Public domain.