Well, both of the PA faires have their seasons in the latter half of the year, and they allow weapons. There's PARF, and also Pittsburg.
The Pitt faire is a bit of a haul from the DC area, but it's a charming little faire. It's not huge, but has a nice look and feel, and their jousting show has a lot of showmanship.
I like PARF. I just wish they didn't have so much pavement on the site. But then again, it probably makes it more handicap-friendly. The entrance fees are a little higher than I'm used to as well.