The summer rainy season just started this month in earnest. There is a good chance there will be some kind of rain in the afternoon almost every day. When it begins and how heavy can vary. If it is already raining, then no go. If it looks like rain, but hasn't started yet, then I will ride. I don't mind being caught in the rain as long as there is no lightning. I fact when it is 90 degrees out I welcome some rain. Don't like getting my shoes and socks wet though.