I Plan to visit Hong Kong in First week of August. Will be rain too much that it will ruin our trip?

According to the previous statistics, the temperature may range from 75 F to 85 F. You are right. There will have frequent heavy rainy days because August is the typhoon season of this area. The weather may influence the sightseeing. If possible, you are advised to change the travel plan. November to May next year would be a nice time for touring around. :)