September weather in San Bruno, CA
The average temperature in San Bruno in September is 62.9°F (53.4°F–72.3°F). Average precipitation: 0.11 inches.
September is a fall month in San Bruno, and is warmer than the annual average of 57.4°F. Daily temperatures swing about 18.9°F between overnight low and afternoon high. Expect about 2 days with precipitation. Daylight averages about 12h 14m. For travel, September is one of the best months of the year to visit.
Avg High
72.3°F
Avg Low
53.4°F
Precipitation
0.11 in
Daylight
12h 14m
September records in San Bruno
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 89.1°F (2002) | 27.0°F (1994) | 0.25 in (2000) |
| September 2 | 90.0°F (2002) | 36.0°F (1994) | 0.06 in (1985) |
| September 3 | 86.0°F (2008) | 46.9°F (1989) | 0.15 in (2003) |
| September 4 | 90.0°F (2004) | 46.0°F (1989) | 0.01 in (2012) |
| September 5 | 89.1°F (2004) | 48.0°F (1989) | 0.00 in (1984) |
| September 6 | 89.1°F (2004) | 46.9°F (1994) | 0.01 in (2011) |
| September 7 | 87.1°F (1984) | 50.0°F (1999) | 0.12 in (1985) |
| September 8 | 98.1°F (1984) | 48.0°F (1988) | 0.52 in (1985) |
| September 9 | 88.0°F (1984) | 46.9°F (1996) | 0.31 in (1999) |
| September 10 | 82.0°F (2002) | 50.0°F (1986) | 0.03 in (1992) |
| September 11 | 88.0°F (2003) | 46.9°F (1988) | 0.00 in (1984) |
| September 12 | 91.0°F (2003) | 46.9°F (1988) | 0.00 in (1984) |
| September 13 | 91.9°F (2003) | 46.9°F (1988) | 0.02 in (2000) |
| September 14 | 78.1°F (2004) | 48.0°F (1991) | 0.04 in (1997) |
| September 15 | 84.9°F (1994) | 46.9°F (1991) | 0.13 in (1996) |
| September 16 | 82.0°F (1987) | 48.9°F (1988) | 0.39 in (1989) |
| September 17 | 88.0°F (1984) | 48.0°F (1991) | 0.62 in (1986) |
| September 18 | 91.0°F (2000) | 48.0°F (1991) | 0.10 in (1989) |
| September 19 | 91.0°F (2000) | 48.0°F (1993) | 0.13 in (1984) |
| September 20 | 91.0°F (2000) | 48.9°F (1987) | 0.25 in (2005) |
| September 21 | 93.9°F (2003) | 46.9°F (1985) | 0.00 in (1984) |
| September 22 | 91.0°F (2003) | 48.0°F (1985) | 0.41 in (2007) |
| September 23 | 87.1°F (1997) | 46.0°F (1988) | 0.23 in (1990) |
| September 24 | 89.1°F (1997) | 45.0°F (1993) | 0.75 in (1986) |
| September 25 | 87.1°F (2010) | 46.0°F (1993) | 0.12 in (1995) |
| September 26 | 88.0°F (1984) | 48.0°F (1996) | 0.15 in (1986) |
| September 27 | 91.0°F (2010) | 46.9°F (2012) | 0.29 in (1986) |
| September 28 | 89.1°F (1984) | 48.0°F (1987) | 0.00 in (1984) |
| September 29 | 87.1°F (1988) | 48.0°F (1993) | 0.10 in (1998) |
| September 30 | 93.0°F (2001) | 48.0°F (2010) | 0.05 in (1984) |