September weather in San Diego, CA
The average temperature in San Diego in September is 72.5°F (63.6°F–81.4°F). Average precipitation: 0.17 inches.
September is a fall month in San Diego, and is warmer than the annual average of 64.1°F. Daily temperatures swing about 17.8°F between overnight low and afternoon high. Expect about 1 days with precipitation. Daylight averages about 12h 11m. For travel, September is a comfortable month to visit.
Avg High
81.4°F
Avg Low
63.6°F
Precipitation
0.17 in
Daylight
12h 11m
September records in San Diego
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 102.0°F (2017) | 55.9°F (2010) | 0.01 in (2004) |
| September 2 | 100.9°F (2017) | 57.9°F (1999) | 0.02 in (2023) |
| September 3 | 104.0°F (2007) | 55.9°F (1999) | 0.07 in (1998) |
| September 4 | 95.0°F (2009) | 57.0°F (2000) | 0.02 in (2022) |
| September 5 | 102.0°F (2020) | 57.9°F (2000) | 0.04 in (2011) |
| September 6 | 106.0°F (2020) | 57.0°F (2000) | 0.11 in (2002) |
| September 7 | 97.0°F (2011) | 60.1°F (2010) | 0.14 in (2002) |
| September 8 | 102.9°F (2024) | 61.0°F (1999) | 0.01 in (2017) |
| September 9 | 99.0°F (2015) | 57.0°F (2000) | 0.39 in (2022) |
| September 10 | 96.1°F (2015) | 55.0°F (2010) | 0.00 in (1998) |
| September 11 | 93.9°F (2000) | 57.9°F (2000) | 0.00 in (1998) |
| September 12 | 93.0°F (2000) | 57.0°F (2005) | 0.00 in (1998) |
| September 13 | 90.0°F (2014) | 57.9°F (2001) | 0.00 in (1998) |
| September 14 | 107.1°F (2012) | 1.2°F (2009) | 0.00 in (1998) |
| September 15 | 102.0°F (2012) | 55.9°F (2016) | 1.02 in (2015) |
| September 16 | 102.9°F (2014) | 55.9°F (1999) | 1.08 in (2014) |
| September 17 | 100.0°F (2020) | 55.0°F (2024) | 0.05 in (2025) |
| September 18 | 100.9°F (2020) | 57.0°F (2010) | 0.21 in (2025) |
| September 19 | 91.0°F (2020) | 55.9°F (1999) | 0.01 in (2005) |
| September 20 | 99.0°F (2015) | 54.0°F (1999) | 0.21 in (2016) |
| September 21 | 98.1°F (2021) | 53.1°F (2007) | 0.16 in (2016) |
| September 22 | 95.0°F (2021) | 57.0°F (2010) | 0.08 in (2007) |
| September 23 | 102.9°F (2009) | 54.0°F (2007) | 0.01 in (2011) |
| September 24 | 93.0°F (2009) | 55.0°F (2007) | 0.00 in (1998) |
| September 25 | 96.1°F (2016) | 55.9°F (2005) | 0.00 in (1998) |
| September 26 | 100.0°F (2016) | 57.0°F (1998) | 0.03 in (1998) |
| September 27 | 107.1°F (2010) | 53.1°F (2013) | 0.01 in (2007) |
| September 28 | 93.0°F (2005) | 55.0°F (1998) | 0.05 in (2019) |
| September 29 | 99.0°F (1999) | 55.9°F (1999) | 0.12 in (2002) |
| September 30 | 104.0°F (2020) | 52.0°F (2019) | 0.21 in (2010) |