Bermuda is on the same latitude as North Carolina (it's about 700 miles or so off the coast) so the temperature will likely be about about the same -- on the cool side, definitely not hot. Also, since the island is fairly small, it'll likely be foggy, maybe wet. So I would suggest bringing clothes for cool weather, and a couple of jackets (one a rain coat).
Edit:
http://www.weather.bm/
Check this out. Looks like it will be in the 60's. So, not that cold, but rainy.