Searles Valley climate

Searles Valley Frost Dates and Growing Season

NOAA 1991-2020 normals for Trona, 1.2 km from Searles Valley, elevation 1695 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Trona. 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 15 and the first fall freeze around November 28, a growing season of about 285 days.

Median at 36°F
last March 4, first November 17
Median at 32°F
last February 15, first November 28
Median at 28°F
last January 23, first December 10

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 4Mar 24Mar 13Mar 8Mar 4Mar 1Feb 27Feb 21Feb 12
32°FMar 4Feb 28Feb 24Feb 19Feb 15Feb 10Feb 4Jan 31Jan 21
28°FFeb 19Feb 10Feb 3Jan 31Jan 23Jan 16Jan 10Jan 4Dec 29
24°FFeb 7Jan 31Jan 21Jan 12Jan 7Jan 2Dec 30Dec 23Dec 13
20°FFeb 4Jan 27Jan 14Jan 8Jan 3Dec 31Dec 25Dec 19Nov 17
16°FFeb 13Feb 2Jan 22Jan 9Jan 2Dec 23Nov 18Nov 13Nov 8

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°FNov 3Nov 8Nov 11Nov 14Nov 17Nov 20Nov 23Nov 27Dec 2
32°FNov 11Nov 16Nov 21Nov 25Nov 28Dec 1Dec 5Dec 10Dec 16
28°FNov 18Nov 27Dec 1Dec 6Dec 10Dec 14Dec 19Dec 25Jan 2
24°FNov 25Dec 5Dec 11Dec 17Dec 23Dec 27Jan 1Jan 6Jan 23
20°FNov 11Dec 4Dec 17Dec 24Dec 28Jan 1Jan 6Jan 15Jan 30
16°FNov 7Nov 11Nov 15Dec 11Dec 31Jan 2Jan 14Jan 30Feb 11

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°F283273267261257251246237226
32°F315305298292285280275268259
28°F350341334329321314307298288
24°F365365364358352345337330314
20°F365365365365365365362352333
16°F365365365365365365365365360

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
97% of years
24°F or colder
71% of years
20°F or colder
32% of years
16°F or colder
11% 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
2,053
Cooling degree days, base 65°F
3,311
Growing degree days, base 40°F
10,419
Growing degree days, base 45°F
8,681
Growing degree days, base 50°F
7,073
Growing degree days, base 55°F
5,644
Growing degree days, base 60°F
4,395

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January546043
February3523118
March20222293
April81103475
May16317766
June15741,023
July07911,255
August07671,232
September0536985
October31187622
November26611221
December558039

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 1.2 km from Searles Valley. 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 USC00049035 (Trona). Public domain.