Taft Heights Frost Dates and Growing Season

NOAA 1991-2020 normals for Taft, 4.3 km from Taft Heights, elevation 773 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Taft. 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 December 17, a growing season of about 330 days.

Median at 36°F: last February 26, first December 3
Median at 32°F: last January 24, first December 17
Median at 28°F: last January 3, first December 27

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	Apr 8	Mar 29	Mar 18	Mar 5	Feb 26	Feb 18	Feb 7	Jan 31	Jan 22
32°F	Mar 12	Feb 23	Feb 8	Jan 31	Jan 24	Jan 17	Jan 10	Jan 2	Dec 25
28°F	Feb 13	Jan 25	Jan 14	Jan 7	Jan 3	Dec 31	Dec 29	Dec 23	Dec 13
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	Nov 15	Nov 23	Nov 27	Nov 30	Dec 3	Dec 6	Dec 10	Dec 15	Dec 24
32°F	Dec 1	Dec 5	Dec 10	Dec 13	Dec 17	Dec 23	Dec 29	Jan 4	Jan 15
28°F	Dec 6	Dec 12	Dec 18	Dec 23	Dec 27	Dec 31	Jan 3	Jan 10	Jan 27
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	318	305	295	286	277	267	257	246	233
32°F	363	351	343	336	330	323	312	299	279
28°F	365	365	365	365	365	362	356	349	336
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: 100% of years
32°F or colder: 91% of years
28°F or colder: 44% 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: 1,935
Cooling degree days, base 65°F: 2,206
Growing degree days, base 40°F: 9,401
Growing degree days, base 45°F: 7,612
Growing degree days, base 50°F: 5,940
Growing degree days, base 55°F: 4,462
Growing degree days, base 60°F: 3,222

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	471	0	67
February	324	1	120
March	199	19	292
April	125	59	386
May	33	195	628
June	4	340	786
July	0	565	1,031
August	0	524	989
September	1	368	817
October	48	127	544
November	254	7	216
December	476	0	65

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 4.3 km from Taft Heights. 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 USC00048752 (Taft). Public domain.