Venice (Venezia) weather in September

Venice regulars on the forum rate September highly: pleasant enough for outdoor dinners without daytime sightseeing turning unpleasant, occasional rain but rarely the kind of flooding (acqua alta) that shows up in the winter months.

The May question on this board is mosquitoes, and the answers are consistent: early May is better than late, the canals themselves are not the problem because the water moves, and the trouble comes from standing water in the gardens and quieter corners. A room with working air conditioning is the practical defence, repellent the other. On weather they promise warm rather than hot with showers and the odd thunderstorm, and our 135.4mm across 12.9 days says the showers are not a formality. High water belongs to autumn and winter but has turned up in mid-May more than once. Days reach 21.6C over 13.6C nights. The record: humidity 76 percent, 11.1 hours of sun and AQI 57.

Venice-forum threads on the risk of heavy rain and flooding in November are candid it's genuinely the highest-risk month for acqua alta, the high water that floods St. Mark's Square and a handful of the lowest-lying streets when a full moon coincides with a strong onshore wind. Posters are equally consistent it's not a daily event and rarely a reason to cancel a trip: an actual flood typically lasts only a couple of hours around high tide before draining away, and the barrier system completed since has cut down on the worst events. The standing packing advice across threads is real waterproof boots over stylish ones, since raised walkways only go up in the worst spots. Regulars call the quieter crowds and moody, atmospheric light a genuine trade worth the wetter forecast. The record: 13.1C days feeling like 11C, 6C nights, a notably high 121mm across 10.9 days, 80 percent humidity and 6.1 hours of sun.

Venice forum regulars call August genuinely hot, humid and the most crowded month, not a gentle continuation of July: “the average August temperature...is 27°C but it can get over 30°C with fairly high humidity.” Rain is a real possibility even at peak heat — still hot with a possibility of rain, but warm, so bringing a summer wardrobe plus an umbrella is standard advice. The workaround regulars share: step 50-100 meters off the main tourist path and the crowds vanish, and late August specifically often brings a thunderstorm-driven break in the heat after the 15th, with many locals returning from their own holidays by then. One genuine reassurance: Acqua Alta flood risk is “very, very low” in August, unlike autumn and winter. Our record: 27.6°C days, feels-like 31°C, 9.2 rain days and a 26.8°C sea — hot and humid with real rain risk, matching the “hot, crowded, but manageable with the right timing” read.

Venice forum regulars call April a genuine transition, cool at the start and warming through the month: “daily maximum average temperatures...are 17°C,” with quite sharp showers passing through from time to time rather than settling in. Weather stays changeable and not easy to predict but unlikely to be very warm, the same spring unpredictability the city carries into May. The clearest planning note isn't about the sky at all: crowds start building through April and are in “full swing” by May, so an early-April visit still catches the quieter window. Some visitors who caught a good stretch admit they may have simply been lucky rather than counting on a reliable pattern. Our record: 15.7°C days, 8.7°C nights, 8.8 rain days and 10.5 hours of sun — mild with real shower risk, matching the “warming but unpredictable” read.