Corcoran climate

Corcoran Frost Dates and Growing Season

NOAA 1991-2020 normals for Corcoran Irrig Dist, 2 km from Corcoran, elevation 200 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Corcoran Irrig Dist. 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 27, a growing season of about 285 days.

Median at 36°F
last March 20, first November 12
Median at 32°F
last February 15, first November 27
Median at 28°F
last January 16, first December 8

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 13Apr 7Apr 2Mar 26Mar 20Mar 13Mar 8Feb 28Feb 19
32°FMar 10Mar 3Feb 26Feb 20Feb 15Feb 9Feb 3Jan 29Jan 17
28°FFeb 11Feb 3Jan 29Jan 23Jan 16Jan 8Jan 1Dec 27Dec 18
24°FJan 22Jan 12Jan 5Jan 1Dec 30Dec 25Dec 21Dec 15Dec 9
20°FJan 18Jan 7Dec 31Dec 30Dec 27Dec 22Dec 19Dec 14Dec 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 29Nov 2Nov 5Nov 9Nov 12Nov 15Nov 18Nov 21Nov 27
32°FNov 12Nov 17Nov 21Nov 24Nov 27Nov 30Dec 2Dec 6Dec 13
28°FNov 24Nov 29Dec 2Dec 4Dec 8Dec 13Dec 19Dec 28Jan 5
24°FDec 3Dec 7Dec 11Dec 15Dec 18Dec 23Dec 29Jan 1Jan 7
20°FDec 5Dec 10Dec 14Dec 19Dec 23Dec 28Dec 30Jan 1Jan 6
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°F266257250244237232224217208
32°F320308299293285279272264254
28°F362349341335330324318308297
24°F365365365365365358350344336
20°F365365365365365365365365357
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
93% of years
24°F or colder
49% of years
20°F or colder
15% of years
16°F or colder
1% 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
2,383
Cooling degree days, base 65°F
1,924
Growing degree days, base 40°F
8,680
Growing degree days, base 45°F
6,943
Growing degree days, base 50°F
5,369
Growing degree days, base 55°F
4,008
Growing degree days, base 60°F
2,867

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January567027
February382078
March2675213
April13639354
May34169600
June3342789
July0505970
August0465930
September3313761
October7085481
November3412142
December581025

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 km from Corcoran. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00042012 (Corcoran Irrig Dist). Public domain.