September weather in Mercedes, TX
The average temperature in Mercedes in September is 82.4°F (72.8°F–92.0°F). Average precipitation: 5.64 inches.
September is a fall month in Mercedes, and is warmer than the annual average of 75°F. Daily temperatures swing about 19.2°F between overnight low and afternoon high. Daylight averages about 12h 9m. For travel, September is a wet month.
Avg High
92.0°F
Avg Low
72.8°F
Precipitation
5.64 in
Daylight
12h 9m
September records in Mercedes
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 102.9°F (2000) | 66.9°F (1915) | 2.74 in (1975) |
| September 2 | 102.0°F (1939) | 68.0°F (1921) | 2.45 in (1990) |
| September 3 | 102.9°F (2000) | 61.0°F (1997) | 1.04 in (2004) |
| September 4 | 102.9°F (2000) | 66.0°F (1919) | 3.10 in (2010) |
| September 5 | 104.0°F (2000) | 63.0°F (1974) | 15.00 in (1933) |
| September 6 | 107.1°F (2000) | 57.9°F (1974) | 1.18 in (1998) |
| September 7 | 104.0°F (2000) | 57.9°F (1918) | 5.75 in (1925) |
| September 8 | 100.0°F (2023) | 59.0°F (1918) | 0.87 in (1969) |
| September 9 | 102.0°F (2023) | 59.0°F (1918) | 1.80 in (2000) |
| September 10 | 102.0°F (2023) | 62.1°F (1994) | 2.01 in (1948) |
| September 11 | 102.0°F (2023) | 66.0°F (1918) | 1.64 in (1998) |
| September 12 | 104.0°F (1937) | 63.0°F (1959) | 3.32 in (1955) |
| September 13 | 100.9°F (1950) | 60.1°F (1940) | 2.00 in (2014) |
| September 14 | 100.0°F (1930) | 61.0°F (1940) | 2.97 in (1961) |
| September 15 | 102.0°F (2023) | 59.0°F (1945) | 4.70 in (1951) |
| September 16 | 102.0°F (2023) | 57.0°F (1945) | 1.96 in (2008) |
| September 17 | 102.9°F (1946) | 59.0°F (1934) | 2.91 in (1998) |
| September 18 | 100.0°F (1920) | 59.0°F (1981) | 4.02 in (1971) |
| September 19 | 100.0°F (1920) | 57.0°F (1981) | 2.46 in (1941) |
| September 20 | 102.0°F (1947) | 57.9°F (1991) | 2.75 in (1967) |
| September 21 | 102.0°F (1947) | 57.9°F (1918) | 7.33 in (1967) |
| September 22 | 100.0°F (1937) | 55.9°F (1938) | 2.27 in (1974) |
| September 23 | 100.0°F (1937) | 55.9°F (1995) | 2.83 in (1992) |
| September 24 | 99.0°F (1920) | 55.9°F (1975) | 4.48 in (1946) |
| September 25 | 100.0°F (1940) | 57.0°F (1914) | 3.70 in (2006) |
| September 26 | 99.0°F (1920) | 57.0°F (2000) | 1.94 in (1970) |
| September 27 | 100.9°F (2011) | 53.1°F (1940) | 1.83 in (1936) |
| September 28 | 99.0°F (1953) | 48.0°F (1942) | 3.29 in (1987) |
| September 29 | 99.0°F (1920) | 51.1°F (1918) | 1.79 in (1981) |
| September 30 | 99.0°F (1938) | 53.1°F (1918) | 8.50 in (1985) |