Yermo climate

Yermo Frost Dates and Growing Season

NOAA 1991-2020 normals for Barstow Daggett AP, 6.5 km from Yermo, elevation 1917 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Barstow Daggett AP. 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 February 19 and the first fall freeze around November 26, a growing season of about 279 days.

Median at 36°F
last March 11, first November 16
Median at 32°F
last February 19, first November 26
Median at 28°F
last January 28, first December 9

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 6Mar 28Mar 21Mar 16Mar 11Mar 7Mar 2Feb 26Feb 18
32°FMar 11Mar 4Feb 28Feb 24Feb 19Feb 13Feb 7Feb 1Jan 23
28°FFeb 25Feb 15Feb 7Feb 2Jan 28Jan 19Jan 13Jan 5Dec 29
24°FFeb 6Jan 29Jan 20Jan 12Jan 7Jan 1Dec 28Dec 22Dec 12
20°FJan 21Jan 14Jan 10Jan 8Jan 3Dec 31Dec 28Dec 21Dec 10
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 31Nov 5Nov 9Nov 12Nov 16Nov 18Nov 21Nov 24Nov 29
32°FNov 10Nov 16Nov 20Nov 23Nov 26Nov 30Dec 3Dec 6Dec 11
28°FNov 22Nov 27Dec 1Dec 6Dec 9Dec 12Dec 16Dec 21Jan 1
24°FDec 1Dec 8Dec 12Dec 18Dec 22Dec 27Jan 1Jan 6Jan 21
20°FDec 9Dec 19Dec 25Dec 30Jan 1Jan 4Jan 8Jan 12Jan 20
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°F274267259253247241234226215
32°F309299292286279274269261252
28°F349338332324317310304295283
24°F365365365358351345340332320
20°F365365365365365365365365353
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
98% of years
24°F or colder
68% of years
20°F or colder
20% of years
16°F or colder
2% 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
2,019
Cooling degree days, base 65°F
3,130
Growing degree days, base 40°F
10,250
Growing degree days, base 45°F
8,492
Growing degree days, base 50°F
6,868
Growing degree days, base 55°F
5,435
Growing degree days, base 60°F
4,196

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January502052
February3431119
March20421290
April8395463
May18303750
June15601,010
July07631,228
August07281,194
September1485935
October45163583
November27810208
December544039

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 6.5 km from Yermo. 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 USW00023161 (Barstow Daggett AP). Public domain.