Matlacha Frost Dates and Growing Season

NOAA 1991-2020 normals for Ft Myers Page Fld AP, 21.4 km from Matlacha, elevation 15 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Ft Myers Page Fld AP. 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 14 percent of years at Ft Myers Page Fld AP, so there is no typical freeze season.

Median at 36°F: last January 21, first January 12
Median at 32°F: last January 16, 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	Feb 15	Feb 6	Feb 1	Jan 29	Jan 21	Jan 15	Jan 10	Jan 5	Dec 31
32°F	Feb 2	Jan 31	Jan 28	Jan 20	Jan 16	Jan 11	Jan 9	Jan 6	Jan 1
28°F	–	–	–	–	–	–	–	–	–
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 23	Jan 1	Jan 4	Jan 8	Jan 12	Jan 17	Jan 24	Jan 31	Feb 6
32°F	Dec 31	Jan 5	Jan 7	Jan 10	Jan 13	Jan 17	Jan 24	Jan 31	Feb 2
28°F	–	–	–	–	–	–	–	–	–
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	365	365	365	358	348	337	328
32°F	365	365	365	365	365	365	365	365	353
28°F	365	365	365	365	365	365	365	365	365
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: 49% of years
32°F or colder: 14% of years
28°F or colder: 1% of years
24°F or colder: 0% 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: 252
Cooling degree days, base 65°F: 4,046
Growing degree days, base 40°F: 12,919
Growing degree days, base 45°F: 11,095
Growing degree days, base 50°F: 9,274
Growing degree days, base 55°F: 7,467
Growing degree days, base 60°F: 5,708

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	98	87	458
February	51	116	485
March	22	187	631
April	2	296	744
May	0	443	908
June	0	519	969
July	0	563	1,028
August	0	570	1,035
September	0	514	965
October	2	404	868
November	16	212	647
December	62	133	538

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 21.4 km from Matlacha. 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 USW00012835 (Ft Myers Page Fld AP). Public domain.