September weather in Bay St. Louis, MS
The average temperature in Bay St. Louis in September is 77.9°F (70.0°F–85.7°F). Average precipitation: 5.72 inches.
September is a fall month in Bay St. Louis, and is warmer than the annual average of 67°F. Daily temperatures swing about 15.7°F between overnight low and afternoon high. Expect about 9 days with precipitation. Daylight averages about 12h 10m. For travel, September is a wet month.
Avg High
85.7°F
Avg Low
70.0°F
Precipitation
5.72 in
Daylight
12h 10m
September records in Bay St. Louis
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 95.0°F (1997) | 64.0°F (1992) | 3.69 in (2008) |
| September 2 | 93.0°F (1989) | 64.0°F (1992) | 2.51 in (1998) |
| September 3 | 95.0°F (1995) | 64.0°F (1987) | 2.20 in (2011) |
| September 4 | 95.0°F (1986) | 64.9°F (1987) | 2.55 in (1988) |
| September 5 | 95.0°F (2000) | 60.1°F (1987) | 4.00 in (1989) |
| September 6 | 97.0°F (1989) | 59.0°F (2011) | 1.40 in (2024) |
| September 7 | 93.0°F (2004) | 55.9°F (1988) | 2.91 in (2002) |
| September 8 | 91.9°F (2004) | 57.0°F (1988) | 3.44 in (2000) |
| September 9 | 95.0°F (1987) | 60.1°F (1988) | 2.40 in (2000) |
| September 10 | 91.9°F (1987) | 60.1°F (2011) | 0.61 in (2024) |
| September 11 | 91.9°F (1987) | 57.9°F (1999) | 3.70 in (1998) |
| September 12 | 91.9°F (1986) | 59.0°F (1999) | 2.49 in (1983) |
| September 13 | 93.9°F (2010) | 59.0°F (2015) | 4.20 in (1998) |
| September 14 | 93.9°F (1987) | 59.0°F (2015) | 1.59 in (2023) |
| September 15 | 93.0°F (1987) | 62.1°F (1986) | 2.98 in (1993) |
| September 16 | 93.9°F (1982) | 57.9°F (1999) | 3.78 in (1994) |
| September 17 | 91.9°F (1982) | 57.9°F (2003) | 1.40 in (1988) |
| September 18 | 91.9°F (1987) | 55.9°F (1999) | 1.66 in (1998) |
| September 19 | 93.9°F (2004) | 55.9°F (1999) | 1.42 in (2016) |
| September 20 | 91.0°F (1991) | 61.0°F (1991) | 1.25 in (2001) |
| September 21 | 90.0°F (1988) | 57.0°F (2006) | 1.75 in (2008) |
| September 22 | 91.9°F (1988) | 46.9°F (1983) | 0.54 in (2003) |
| September 23 | 93.0°F (1997) | 46.0°F (1982) | 0.92 in (1998) |
| September 24 | 91.9°F (1988) | 48.0°F (1982) | 0.53 in (2023) |
| September 25 | 91.0°F (1988) | 48.0°F (1982) | 2.92 in (2002) |
| September 26 | 90.0°F (1986) | 48.0°F (1982) | 7.72 in (2002) |
| September 27 | 90.0°F (1984) | 42.1°F (2006) | 1.10 in (1992) |
| September 28 | 91.0°F (1986) | 48.9°F (2006) | 2.60 in (1998) |
| September 29 | 91.0°F (2007) | 43.0°F (2006) | 1.78 in (2012) |
| September 30 | 91.9°F (2016) | 48.0°F (2006) | 1.54 in (1989) |