Been twice before this time of year and going the same time as you. Don't worry about it. The mornings are usually nice with a briefs down pour in the afternoon. Rarely and entire day rain out altough we did have one of those on our first trip. Don't let it stop you from doing what you want. We should still see more sun than not.
I wouldn't give a second thought to the possibility of rain. You can't control it, don't worry about it. Wear light clothing. If it rains, get wet. When the sun comes back you'll dry out in about six minutes.