The region in summer is certainly hot and very muggy so be warned on that front — but the rains come quickly and can soothe and break the heat beautifully, and the sightseeing to be done, by car, train, bike or more in that region, the flatness of the valley stretching out for miles but the foothills of the Alps not far away, can’t be described. Just go, and remember not to limit yourself to Venezia itself — there’s much more to see.