This weather has a price Keeping the median San Diego County home comfortable runs roughly $596 a year in heating and cooling alone. See where it lands in the monthly bill

30-year climate normals

San Diego County Climate and Weather Averages

Hottest month: August

90.8°

average daily high. The coldest month is December, averaging a low of 35.6°F.

San Diego County gets 14.65" of precipitation a year, and 62% of it falls in Jan, Feb, Mar.

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	66.2°	36.5°	3.10"
February	65.9°	37.9°	3.66"
March	67.7°	39.8°	2.30"
April	71.7°	42.8°	1.00"
May	75.5°	48.9°	0.41"
June	82.9°	52.0°	0.06"
July	88.9°	57.5°	0.10"
August	90.8°	58.7°	0.04"
September	87.4°	54.9°	0.15"
October	80.0°	48.5°	0.69"
November	72.5°	40.3°	1.06"
December	65.6°	35.6°	2.08"

Rainfall by month

San Diego County has a distinct wet season. 62% of the year's precipitation arrives in Jan, Feb, Mar.

January 3.10"

February 3.66"

March 2.30"

April 1.00"

May 0.41"

June 0.06"

July 0.10"

August 0.04"

September 0.15"

October 0.69"

November 1.06"

December 2.08"

Annual total 14.65"

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 957

Heating degree days How much heating the climate demands 2,329

Approximate annual cooling cost At 33.61¢/kWh, California average $322

Approximate annual electric heating cost Lower where heating is gas rather than electric $274

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 Diego County, where electricity is one line of eight.

Common questions

What is the weather like in San Diego County?

San Diego County averages a high of 90.8°F in August and a low of 35.6°F in December. Annual precipitation is 14.65 inches, with essentially no snow.

When is the rainy season in San Diego County?

The wettest stretch is Jan, Feb, Mar, which accounts for 62% 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 Diego County?

The average daily high in August, the hottest month, is 90.8°F. That drives 957 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in San Diego County?

The weather station used for San Diego County, RAMONA AP, CA US, reports temperature and precipitation but not snowfall, so there is no snow normal to quote here. Precipitation that falls as snow is still counted in the 14.65 inches above, measured as melted water.

Sources

Temperature, precipitation and snowfall normals: NOAA National Centers for Environmental Information, 1991 to 2020 Monthly Climate Normals, station RAMONA AP, CA US (USW00053120), 8.1 miles from the county centroid.
Heating and cooling degree days: NOAA, same station and period.
Annual figures on this page are the sum of that station's twelve monthly normals. NOAA also publishes a separately-computed annual normal, which can differ from the monthly sum by a few percent; we use the monthly series because the month-by-month breakdown above has to come from it.
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.