September usually has some very good days, typically 50% chance of sunshine and 50% overcast/light rain and like April, you can also expect tropical storms in the early evening, often with incredibly strong winds. There were only 4 such windy storms this year. September is also a warm month and before the transition to the cool season.
The above is what you can normally expect. It wasn't what actually happened this year, we still had some very bad rainstorms in September this year and lots of local flooding.