Stockton climate

Stockton Frost Dates and Growing Season

NOAA 1991-2020 normals for Stockton Fire Stn 4, 5.2 km from Stockton, elevation 12 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Stockton Fire Stn 4. 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 5 and the first fall freeze around December 8, a growing season of about 305 days.

Median at 36°F
last March 4, first November 20
Median at 32°F
last February 5, first December 8
Median at 28°F
last January 11, first December 23

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 13Mar 29Mar 16Mar 9Mar 4Feb 28Feb 21Feb 13Feb 1
32°FMar 11Feb 28Feb 19Feb 12Feb 5Jan 28Jan 17Jan 6Dec 27
28°FFeb 21Feb 3Jan 28Jan 19Jan 11Jan 4Dec 30Dec 23Dec 12
24°FJan 29Jan 25Jan 16Jan 6Jan 3Dec 31Dec 27Dec 15Dec 8
20°F–––––––––
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°FNov 3Nov 8Nov 12Nov 16Nov 20Nov 25Dec 1Dec 5Dec 13
32°FNov 17Nov 24Nov 28Dec 2Dec 8Dec 13Dec 19Dec 27Jan 6
28°FDec 1Dec 7Dec 13Dec 18Dec 23Dec 29Jan 3Jan 12Jan 29
24°FDec 7Dec 13Dec 21Dec 28Dec 31Jan 3Jan 7Jan 19Jan 26
20°F–––––––––
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°F295282273266260252244234219
32°F344331323314305296286277262
28°F365365365361353345336328310
24°F365365365365365365365365355
20°F365365365365365365365365365
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
97% of years
28°F or colder
59% of years
24°F or colder
13% of years
20°F or colder
0% of years
16°F or colder
0% 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
2,049
Cooling degree days, base 65°F
1,650
Growing degree days, base 40°F
8,733
Growing degree days, base 45°F
6,947
Growing degree days, base 50°F
5,277
Growing degree days, base 55°F
3,832
Growing degree days, base 60°F
2,627

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January504042
February3260112
March2318248
April12440367
May36149578
June3283731
July0398863
August0383848
September2287735
October5698507
November2664198
December501048

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 5.2 km from Stockton. 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 USC00048560 (Stockton Fire Stn 4). Public domain.