Its a very good time of the year to be travelling to Coorg and Chikmagalur as they experience rainfall and the weather is really very cool. But right now it is not at all preferable to travel to Coorg or Chikmagalur as the places are flooded by heavy rainfall. Due to heavy rainfall roads are blocked and there's no supply of electricity. So travelling to those places is risky now.
In Ooty also there's rainfall. The town receives heavy rainfall during this season and this might disrupt the routine day sightseeing activity for you. As there is heavy rainfall in most of the place, it's better if u postpone your trip to Ooty from next week to the month of September.