Carpinteria Frost Dates and Growing Season

NOAA 1991-2020 normals for Santa Barbara, 15.4 km from Carpinteria, elevation 16 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Santa Barbara. 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 11 percent of years at Santa Barbara, so there is no typical freeze season.

Median at 36°F: last January 11, first December 30
Median at 32°F: last January 13, first January 6

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 8	Jan 31	Jan 21	Jan 11	Jan 3	Dec 29	Dec 21	Dec 12
32°F	Feb 24	Feb 4	Jan 27	Jan 17	Jan 13	Jan 7	Dec 31	Dec 20	Dec 12
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 5	Dec 13	Dec 19	Dec 24	Dec 30	Jan 3	Jan 11	Jan 29	Feb 10
32°F	Dec 12	Dec 19	Dec 29	Jan 3	Jan 6	Jan 14	Jan 22	Feb 1	Feb 22
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	336	319
32°F	365	365	365	365	365	365	365	365	360
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: 48% of years
32°F or colder: 11% of years
28°F or colder: 3% of years
24°F or colder: 1% 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: 1,427
Cooling degree days, base 65°F: 538
Growing degree days, base 40°F: 8,236
Growing degree days, base 45°F: 6,411
Growing degree days, base 50°F: 4,595
Growing degree days, base 55°F: 2,866
Growing degree days, base 60°F: 1,464

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	262	3	209
February	225	3	201
March	198	7	276
April	133	19	336
May	88	24	401
June	35	40	455
July	7	109	567
August	5	129	589
September	10	118	558
October	43	70	491
November	147	15	318
December	275	1	193

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 15.4 km from Carpinteria. 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 USC00047902 (Santa Barbara). Public domain.