30-year climate normals

San Joaquin County Climate and Weather Averages

Hottest month — July

95.4°

average daily high. The coldest month is December, averaging a low of 38.4°F.

San Joaquin County gets 13.45" of precipitation a year, and 56% of it falls in Dec, Jan, Feb.

Temperature through the year

Each bar spans the average daily low to the average daily high for that month.

Month	Avg high	Avg low	Precip
January	57.0°	39.1°	2.67"
February	62.9°	41.3°	2.50"
March	68.5°	44.2°	1.91"
April	74.5°	47.4°	1.11"
May	82.8°	52.6°	0.57"
June	90.4°	57.6°	0.10"
July	95.4°	60.9°	0.00"
August	94.4°	60.3°	0.01"
September	90.4°	57.5°	0.08"
October	80.3°	50.6°	0.69"
November	66.6°	42.8°	1.40"
December	57.1°	38.4°	2.41"

Rainfall by month

San Joaquin County has a distinct wet season. 56% of the year's precipitation arrives in Dec, Jan, Feb.

January 2.67"

February 2.50"

March 1.91"

April 1.11"

May 0.57"

June 0.10"

July 0.00"

August 0.01"

September 0.08"

October 0.69"

November 1.40"

December 2.41"

Annual total 13.45"

What this climate costs you

Degree days measure how hard a building has to work to stay comfortable. They are the reason two identical houses have very different power bills, and they are the link between the weather here and what you pay every month.

Cooling degree days How much air conditioning the climate demands 1,566

Heating degree days How much heating the climate demands 2,259

Approximate annual cooling cost At 33.25¢/kWh, California average $521

Approximate annual electric heating cost Lower where heating is gas rather than electric $263

These are rough planning figures from degree days and the state electricity price, not a bill estimate. House size, insulation and fuel type move them a lot. See the full cost of owning a home in San Joaquin County, where electricity is one line of eight.

Common questions

What is the weather like in San Joaquin County?

San Joaquin County averages a high of 95.4°F in July and a low of 38.4°F in December. Annual precipitation is 13.45 inches, with essentially no snow.

When is the rainy season in San Joaquin County?

The wettest stretch is Dec, Jan, Feb, which accounts for 56% of the year's precipitation. That is a pronounced wet season rather than rain spread evenly through the year.

How hot does it get in San Joaquin County?

The average daily high in July, the hottest month, is 95.4°F. That drives 1,566 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in San Joaquin County?

Effectively no. Measurable snowfall is rare in San Joaquin County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station STOCKTON METRO AP, CA US (USW00023237), 4.1 miles from the county centroid.
Heating and cooling degree days — NOAA, same station and period.
Electricity price — US Energy Information Administration, Electric Power Monthly Table 5.6.A, California residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.