I was there at 5pm 2 days in a row. I was the first walk in on Wednesday and the 2nd on Thursday. I’ll go earlier than half an hour next time. I could go onto a wait list for a class closer than the one I am in but I don’t really want to give up that spot and then not get into another class. I don’t know the odds but the classes are very busy and July will just bring warm sunny weather. The instructor did tell me that rain normally means a few no shows and a good chance of getting in.