Weather

Venice becomes extremely hot in July and August, but outside these months the weather is not too excessive. However, bear in mind that Venice, due to its location on the Adriatic coast, suffers from frequent thunderstorms and rain showers.

"Acqua alta" - High tide
High tide may exceed ground level - causing the typical phenomenon called "Acqua alta" - in some times of the year: it may occur from October to January
Venetians are quite used to it, and do not complain, though "Acqua alta" causes not little trouble to their schedules: boats may have to follow alternative canals, public boat transportation services undergo a "revolution" during peak days and hours. Water won't (hopefully!) reach a 1 meter level in the streets: measurements refer to the sea level, so expect a 50 cm at worst and have your boots ready. Acqua alta does not last all day: peaks may be in the early morning or in the evening, and this phenomenon may happen from October to early January. The reasons are many: the lagoon is not a static environment: water level is influenced by winds, rain, the Moon, and also from human modifications to the environment.