Indian River County Frost Dates and Growing Season

NOAA 1991-2020 normals for Vero Beach 4SE, 17.5 km from Indian River County, elevation 20 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Vero Beach 4SE. 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 24 percent of years at Vero Beach 4SE, so there is no typical freeze season.

Median at 36°F: last January 27, first January 9
Median at 32°F: last January 18, 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 21	Feb 9	Feb 3	Jan 31	Jan 27	Jan 19	Jan 14	Jan 8	Jan 2
32°F	Feb 11	Jan 31	Jan 29	Jan 23	Jan 18	Jan 13	Jan 8	Jan 4	Dec 30
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 21	Dec 29	Jan 1	Jan 5	Jan 9	Jan 14	Jan 22	Jan 30	Feb 6
32°F	Dec 27	Jan 1	Jan 5	Jan 8	Jan 13	Jan 17	Jan 23	Jan 29	Feb 4
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	362	354	344	335	328	313
32°F	365	365	365	365	365	365	365	359	341
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: 63% of years
32°F or colder: 24% of years
28°F or colder: 5% 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: 350
Cooling degree days, base 65°F: 3,801
Growing degree days, base 40°F: 12,576
Growing degree days, base 45°F: 10,753
Growing degree days, base 50°F: 8,938
Growing degree days, base 55°F: 7,147
Growing degree days, base 60°F: 5,420

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	124	76	425
February	77	94	439
March	39	157	583
April	7	245	689
May	0	385	849
June	0	489	939
July	0	555	1,020
August	0	558	1,023
September	0	509	959
October	2	393	856
November	21	215	644
December	79	126	514

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 17.5 km from Indian River 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 USC00089219 (Vero Beach 4SE). Public domain.