Okinawa Tips

Hello!

Planning to visit Okinawa for about a week the last couple days in September / first week of October.

Just wanted to check if there was anything I should be aware of in terms of weather/temperature, anything being closed at that time? Will there be a lot of Chinese tourists visiting at this time given their national holiday week?

Also, whether to explore the main island or visit one of the other smaller islands for beaches, snorkelling, kayaking, etc? Seeing a lot of mentions of Zamami and the Keramas.

Any other recommendations?

Have been to Japan several times previously, but this will be the first time for Okinawa.

Thank you!