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Weather in San Diego County for September 2025

Your guide to San Diego County weather in September - trends and predictions
  • In general, the average temperature in San Diego County at the beginning of September is 25.6 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 22 °F by the end of September.

  • With an average of 2 rainy days, San Diego County experiences minimal rainfall in September, ensuring that most days remain pleasantly dry.

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Average dry days
28
Dry days
Average rainy days
2
Rainy days
Average snowy days
0
Snow days
Average temperatures
23°/17°
Temperatures
Average wind speed
17 km/h
Avg max wind
Average humidity
74 %
Avg humidity

San Diego County in September average weather

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Temperatures trend during September in San Diego County

See the weather trend as well as the moving average line

September weather day by day

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Date Weather Temperatures Rain UV More
Sept. 1 Cloudy
Cloudy
24° /19° 0 mm 6
Sept. 2 Overcast
Overcast
25° /20° 0 mm 6
Sept. 3 Mist
Mist
24° /20° 0 mm 6
Sept. 4 Overcast
Overcast
25° /20° 0 mm 6
Sept. 5 Overcast
Overcast
26° /20° 0 mm 6
Sept. 6 Overcast
Overcast
27° /21° 0 mm 7
Sept. 7 Cloudy
Cloudy
28° /20° 0 mm 7
Sept. 8 Partly cloudy
Partly cloudy
30° /22° 0 mm 8
Sept. 9 Partly cloudy
Partly cloudy
29° /22° 0 mm 8
Sept. 10 Overcast
Overcast
28° /21° 0 mm 7
Sept. 11 Cloudy
Cloudy
26° /20° 0 mm 6
Sept. 12 Mist
Mist
23° /18° 0 mm 6
Sept. 13 Cloudy
Cloudy
22° /18° 0.1 mm 5
Sept. 14 Cloudy
Cloudy
22° /17° 0 mm 6
Sept. 15 Overcast
Overcast
22° /18° 0 mm 5
Sept. 16 Overcast
Overcast
22° /17° 0.2 mm 5
Sept. 17 Overcast
Overcast
21° /17° 0 mm 5
Sept. 18 Overcast
Overcast
21° /17° 0 mm 5
Sept. 19 Cloudy
Cloudy
22° /16° 0 mm 5
Sept. 20 Patchy rain possible
Patchy rain possible
21° /17° 0.1 mm 5
Sept. 21 Patchy rain possible
Patchy rain possible
21° /15° 0.2 mm 5
Sept. 22 Cloudy
Cloudy
22° /16° 0 mm 5
Sept. 23 Partly cloudy
Partly cloudy
23° /17° 0 mm 6
Sept. 24 Cloudy
Cloudy
23° /16° 0 mm 5
Sept. 25 Partly cloudy
Partly cloudy
23° /16° 0 mm 6
Sept. 26 Overcast
Overcast
21° /15° 0 mm 5
Sept. 27 Cloudy
Cloudy
22° /15° 0 mm 5
Sept. 28 Cloudy
Cloudy
22° /16° 0 mm 5
Sept. 29 Cloudy
Cloudy
22° /15° 0 mm 5
Sept. 30 Patchy rain possible
Patchy rain possible
21° /15° 2.3 mm 5
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Important Notice
Our weather forecast for San Diego County in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the San Diego County forecast closer to your planned date for the most up-to-date weather information.

San Diego County in September - FAQ

What are the expected maximum and minimum temperatures in San Diego County during September?
During September, expect a variety of temperatures with highs around 23° and lows near 17°, suitable for diverse activities and preferences.
How much rainfall should be expected in San Diego County during September?
Rainfall in San Diego County during September is rare to nonexistent, with the total expected rainfall being less than 10 mm and approximately 2 days seeing any precipitation. Planning without the concern for rain is generally straightforward during this very dry period.
What are the typical wind conditions in San Diego County during September?
The average wind speed in San Diego County during September is 17 km/h, suggesting breezy to windy conditions, depending on your activities.
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Location coordinates Where is San Diego County?

Get accurate weather forecasts for San Diego County, located at latitude 32.716 and longitude -117.165. Stay updated with localized weather information tailored for San Diego County.

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