Without a bit more info, it's difficult to say. Weather wise, there is not going to be a big difference. What WILL make the difference is elevation. If you're down along the coastal areas, that time of year is muggy, hot, humid, possibly stormy, and rife with gnats and mosquitos. If you're up in the White Mountains or along the shores of Lake Champlain, it's a whole 'nother story. Less humid, cooler nights, and probably not so many insects. Also be aware that there are a LOT of people around New England, and they all take vacations in July and August.
Always remember, you're a unique individual. Just like the other 7 billion people on the planet...