I planned to visit Hong Kong in mid September .. Will it be ideal date to visit from 17-22?

I just checked the weather records in the past years of that period. Generally, it is a good choice to travel then, because sunny or cloudy days are likely to happen. The temp range shall be 25C (77F) - 32C (90F). Prepare summer clothes and long-sleeved shirt. However, it may also rain a little then, so do check ahead the weather forecast.