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United States › California › San Diego County › Climate Station RAMONA AP, CA US Distance 8.1 mi Normals 1991–2020

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.

40° 60° 80° JanFebMarAprMayJunJulAugSepOctNovDec
MonthAvg highAvg 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 33.25¢/kWh, California average $318
Approximate annual electric heating cost Lower where heating is gas rather than electric $271

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?

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

Sources

  • Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 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.
  • 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.