Indio Hills Frost Dates and Growing Season

NOAA 1991-2020 normals for Indio Fire Stn, 13.7 km from Indio Hills, elevation -21 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Indio Fire Stn. 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 30 percent of years at Indio Fire Stn, so there is no typical freeze season.

Median at 36°F: last January 1, first December 18
Median at 32°F: last December 31, 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	Jan 31	Jan 18	Jan 10	Jan 5	Jan 1	Dec 30	Dec 24	Dec 18	Dec 10
32°F	Jan 21	Jan 10	Jan 5	Jan 1	Dec 31	Dec 28	Dec 22	Dec 15	Dec 10
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	Nov 30	Dec 6	Dec 10	Dec 13	Dec 18	Dec 21	Dec 25	Dec 31	Jan 7
32°F	Dec 8	Dec 13	Dec 17	Dec 23	Dec 27	Dec 30	Jan 1	Jan 5	Jan 13
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	360	355	349	344	338	330	320
32°F	365	365	365	365	365	365	365	360	348
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: 77% of years
32°F or colder: 30% of years
28°F or colder: 2% 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: 706
Cooling degree days, base 65°F: 4,730
Growing degree days, base 40°F: 13,149
Growing degree days, base 45°F: 11,325
Growing degree days, base 50°F: 9,508
Growing degree days, base 55°F: 7,750
Growing degree days, base 60°F: 6,140

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	208	8	268
February	119	39	341
March	41	151	575
April	6	290	734
May	1	503	967
June	0	724	1,174
July	0	904	1,369
August	0	894	1,359
September	0	709	1,160
October	2	410	873
November	77	92	465
December	252	5	223

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 13.7 km from Indio Hills. 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 USC00044259 (Indio Fire Stn). Public domain.