September weather in Grand Isle, LA
The average temperature in Grand Isle in September is °F (°F–°F). Average precipitation: 6.30 inches.
September is a fall month in Grand Isle, and is cooler than the annual average of 0°F. Expect about 9 days with precipitation. Daylight averages about 12h 10m.
Avg High
°F
Avg Low
°F
Precipitation
6.30 in
Daylight
12h 10m
September records in Grand Isle
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 96.1°F (1951) | 70.0°F (1953) | 1.97 in (2000) |
| September 2 | 96.1°F (1949) | 70.0°F (1955) | 3.25 in (1999) |
| September 3 | 97.0°F (1963) | 71.1°F (1955) | 7.83 in (1948) |
| September 4 | 95.0°F (1951) | 70.0°F (1952) | 3.45 in (1949) |
| September 5 | 95.0°F (1950) | 64.9°F (2011) | 2.50 in (1967) |
| September 6 | 93.9°F (1956) | 64.9°F (2011) | 2.00 in (1997) |
| September 7 | 93.9°F (1963) | 66.9°F (1950) | 0.92 in (2000) |
| September 8 | 96.1°F (1951) | 64.0°F (1950) | 3.23 in (2003) |
| September 9 | 96.1°F (1951) | 66.9°F (2011) | 2.84 in (1960) |
| September 10 | 95.0°F (1958) | 68.0°F (1960) | 8.75 in (1960) |
| September 11 | 97.0°F (1949) | 66.0°F (2011) | 0.94 in (2015) |
| September 12 | 95.0°F (1949) | 69.1°F (1960) | 4.95 in (1949) |
| September 13 | 95.0°F (1963) | 66.0°F (1960) | 4.35 in (1990) |
| September 14 | 91.9°F (1950) | 66.9°F (1959) | 1.86 in (1985) |
| September 15 | 95.0°F (1949) | 66.0°F (1959) | 1.00 in (1957) |
| September 16 | 91.9°F (1956) | 64.0°F (1961) | 3.50 in (1954) |
| September 17 | 93.0°F (1949) | 63.0°F (1961) | 2.00 in (1957) |
| September 18 | 97.0°F (1949) | 63.0°F (1961) | 2.00 in (1957) |
| September 19 | 93.9°F (1950) | 62.1°F (1961) | 2.00 in (1966) |
| September 20 | 95.0°F (1956) | 61.0°F (1955) | 1.85 in (2001) |
| September 21 | 93.0°F (1954) | 66.9°F (1951) | 2.87 in (1951) |
| September 22 | 91.9°F (1955) | 69.1°F (1966) | 1.25 in (1958) |
| September 23 | 93.9°F (1950) | 68.0°F (1953) | 0.91 in (1985) |
| September 24 | 91.9°F (1951) | 66.0°F (1961) | 1.26 in (2002) |
| September 25 | 91.9°F (1955) | 68.0°F (1953) | 1.47 in (2007) |
| September 26 | 93.0°F (1958) | 69.1°F (1953) | 9.16 in (2002) |
| September 27 | 93.0°F (1955) | 59.0°F (1967) | 3.51 in (2015) |
| September 28 | 93.0°F (1955) | 54.0°F (1967) | 1.00 in (1996) |
| September 29 | 95.0°F (2011) | 55.0°F (1967) | 6.60 in (2011) |
| September 30 | 93.0°F (1955) | 62.1°F (1957) | 0.63 in (1956) |