Palmdale climate

Palmdale Frost Dates and Growing Season

NOAA 1991-2020 normals for Palmdale, 2.3 km from Palmdale, elevation 2612 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Palmdale. 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 March 10 and the first fall freeze around November 19, a growing season of about 248 days.

Median at 36°F
last April 5, first November 7
Median at 32°F
last March 10, first November 19
Median at 28°F
last February 13, first December 1

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°FApr 26Apr 19Apr 14Apr 9Apr 5Mar 31Mar 26Mar 19Mar 11
32°FApr 11Apr 2Mar 27Mar 18Mar 10Mar 5Feb 28Feb 22Feb 12
28°FMar 17Mar 3Feb 25Feb 19Feb 13Feb 7Feb 2Jan 27Jan 14
24°FFeb 19Feb 8Feb 1Jan 25Jan 15Jan 7Dec 31Dec 24Dec 11
20°FFeb 3Jan 26Jan 13Jan 5Dec 31Dec 27Dec 19Dec 11Dec 4
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°FOct 24Oct 30Nov 1Nov 4Nov 7Nov 9Nov 12Nov 15Nov 21
32°FNov 3Nov 8Nov 12Nov 16Nov 19Nov 22Nov 25Nov 30Dec 4
28°FNov 15Nov 21Nov 25Nov 28Dec 1Dec 5Dec 9Dec 15Dec 23
24°FNov 23Dec 1Dec 5Dec 10Dec 16Dec 22Dec 28Jan 4Jan 19
20°FDec 1Dec 6Dec 13Dec 20Dec 26Dec 31Jan 4Jan 13Feb 1
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°F238230224218213209203197190
32°F282270262254248241234227216
28°F328316308299292283275266251
24°F365356348341334329322312296
20°F365365365365365365359345333
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
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
85% of years
20°F or colder
34% of years
16°F or colder
5% 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
2,520
Cooling degree days, base 65°F
2,047
Growing degree days, base 40°F
8,676
Growing degree days, base 45°F
6,958
Growing degree days, base 50°F
5,415
Growing degree days, base 55°F
4,090
Growing degree days, base 60°F
2,972

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January555032
February416073
March3036194
April16836325
May57150558
June7340783
July05441,009
August0525990
September5348793
October8195480
November3453150
December584028

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 2.3 km from Palmdale. 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 USC00046624 (Palmdale). Public domain.