Inyokern climate

Inyokern Frost Dates and Growing Season

NOAA 1991-2020 normals for Inyokern, 0.9 km from Inyokern, elevation 2430 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Inyokern. 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 9 and the first fall freeze around November 20, a growing season of about 250 days.

Median at 36°F
last April 3, first November 8
Median at 32°F
last March 9, first November 20
Median at 28°F
last February 18, 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 18Apr 13Apr 8Apr 3Mar 30Mar 23Mar 15Mar 9
32°FApr 8Apr 1Mar 24Mar 15Mar 9Mar 4Feb 28Feb 24Feb 16
28°FMar 12Mar 3Feb 27Feb 22Feb 18Feb 11Feb 5Jan 31Jan 21
24°FFeb 25Feb 13Feb 4Jan 28Jan 20Jan 11Jan 4Dec 31Dec 25
20°FFeb 5Jan 25Jan 14Jan 6Jan 1Dec 30Dec 25Dec 20Dec 14
16°FJan 24Jan 11Jan 6Jan 2Dec 29Dec 26Dec 20Dec 15Dec 10

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 5Nov 8Nov 11Nov 14Nov 18Nov 22
32°FNov 2Nov 8Nov 13Nov 17Nov 20Nov 23Nov 26Dec 1Dec 5
28°FNov 14Nov 20Nov 24Nov 28Dec 1Dec 3Dec 6Dec 10Dec 16
24°FNov 24Dec 1Dec 4Dec 8Dec 11Dec 15Dec 19Dec 24Jan 1
20°FDec 1Dec 7Dec 11Dec 16Dec 22Dec 26Dec 30Jan 4Jan 20
16°FDec 5Dec 10Dec 16Dec 21Dec 26Dec 30Jan 3Jan 8Jan 23

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°F246236229223217212206200191
32°F279270263257250244237227217
28°F321310300293286280274267256
24°F354345338333327319312302288
20°F365365365364358351344337325
16°F365365365365365365365365353

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
96% of years
20°F or colder
64% of years
16°F or colder
19% 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
2,431
Cooling degree days, base 65°F
2,389
Growing degree days, base 40°F
9,115
Growing degree days, base 45°F
7,402
Growing degree days, base 50°F
5,858
Growing degree days, base 55°F
4,517
Growing degree days, base 60°F
3,362

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January564031
February416068
March2678225
April12948372
May38200626
June3438885
July06281,093
August05891,054
September3364812
October65110510
November3374161
December609022

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 0.9 km from Inyokern. 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 USC00044278 (Inyokern). Public domain.