Weather in San Diego County in September

General weather information about San Diego County

Average annual temperature is 15.0 °C

Absolute maximum temperature: 38.6 °C

Absolute minimum temperature: -5.3 °C

Number of sunny days: 228 days

Number of rainy days: 136 days

Number of snow days: 1 day

* Weather data for San Diego County United States is based on climate observations for 2026 year

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Absolute maximum temperature (°C)	18.1	19.9	18.0	27.3	26.3	32.5	36.2	38.6	34.3	34.4	27.5	22.7
Average daytime temperature (°C)	12.7	12.5	12.8	19.6	19.2	21.9	32.2	30.7	26.1	25.5	20.4	17.5
Average temperature (°C)	7.9	6.7	7.8	13.1	13.9	15.8	26.1	24.8	20.2	18.1	13.6	11.1
Average night temperature (°C)	4.1	2.2	4.1	8.0	10.2	11.3	20.4	19.5	15.7	12.1	8.1	6.1
Absolute minimum temperature (°C)	-1.0	-5.3	-5.1	-1.0	5.0	8.5	13.9	14.4	11.5	6.9	2.5	1.9

The best time to visit San Diego County during the most sunny months:

The largest precipitation sum in San Diego County is at

January — 322(mm)

February — 142(mm)

March — 321(mm)

When is the best time to visit San Diego County?

The historical weather data above shows the warmest, sunniest and driest months to help you choose the best time to visit San Diego County.

What is the weather like in San Diego County?

See average temperature, rainfall and daylight hours for San Diego County by month in the table above.

How many sunny days does San Diego County have?

The monthly weather statistics above show sunshine and rainfall patterns for San Diego County throughout the year.