I visited Stonehenge in late August and was not disappointed. The day was gray and magical with the sun trying to burn through the clouds. It was worth the extra day it took to get there and back. I found the audio guides to be very valuable to learn about the site (free once you purchase your admission ticket). It is definitely worth paying the few pounds to get in and listen to the tour rather than just looking through the fence. I will never forget it.
My boyfriend and I stayed in Trowbridge (about an hour away) at a lovely old refurbished farm turned hotel called the Old Manor Hotel. It was absolutely beautiful with gardens and antiques in every room. It was a wonderful experience.