Yulee climate

Yulee Frost Dates and Growing Season

NOAA 1991-2020 normals for Fernandina Beach, 15.2 km from Yulee, elevation 49 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Fernandina Beach. 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 February 2 and the first fall freeze around January 4, a growing season of about 333 days.

Median at 36°F
last February 18, first December 19
Median at 32°F
last February 2, first January 4
Median at 28°F
last January 26, 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.

Threshold10%20%30%40%50%60%70%80%90%
36°FMar 13Mar 5Feb 28Feb 23Feb 18Feb 12Feb 6Jan 31Jan 19
32°FMar 1Feb 21Feb 14Feb 8Feb 2Jan 29Jan 22Jan 14Jan 2
28°FFeb 19Feb 9Feb 2Jan 31Jan 26Jan 19Jan 13Jan 7Dec 31
24°FFeb 15Feb 5Feb 1Jan 29Jan 25Jan 18Jan 13Jan 6Dec 30
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.

Threshold10%20%30%40%50%60%70%80%90%
36°FNov 26Dec 1Dec 7Dec 13Dec 19Dec 25Jan 1Jan 6Jan 14
32°FDec 10Dec 19Dec 27Jan 1Jan 4Jan 8Jan 15Jan 24Feb 3
28°FDec 19Dec 29Jan 2Jan 8Jan 13Jan 18Jan 26Feb 1Feb 10
24°FDec 25Jan 2Jan 8Jan 15Jan 19Jan 24Jan 29Feb 1Feb 14
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.

Threshold10%20%30%40%50%60%70%80%90%
36°F334326317308303297290281270
32°F365358347339333327319308299
28°F365365365365362352342333320
24°F365365365365365365365365343
20°F365365365365365365365365365
16°F365365365365365365365365365

How often it gets that cold

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

36°F or colder
99% of years
32°F or colder
85% of years
28°F or colder
52% of years
24°F or colder
20% of years
20°F or colder
3% 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
1,066
Cooling degree days, base 65°F
2,918
Growing degree days, base 40°F
10,984
Growing degree days, base 45°F
9,181
Growing degree days, base 50°F
7,424
Growing degree days, base 55°F
5,768
Growing degree days, base 60°F
4,254

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January32611196
February22518231
March12164413
April32140558
May2337800
June0471921
July05521,017
August0533998
September0438888
October13251704
November9876430
December24927270

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 15.2 km from Yulee. 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 USC00082944 (Fernandina Beach). Public domain.