The rainy season is also very hot, and of course very humid! But it doesn't rain all the time, and you can still enjoy a nice weather most days in the morning and beginning of the afternoon. Usually the sky starts to get cloudy in the afternoon, and it rains in the evenings. If you want to visit Thailand during western summer (July-August), you don't need to worry too much about the rain. You can still get some tan on the beach in the morning, visit some places in the afternoon, and in the evening enjoy a drink somewhere watching the rain falling. You can even go swimming while it's raining, if you want to know what it's like!