Acqua alta at Rialto

When is acqua alta season in Venice in 2026-27?

From October to January, with the most high tides in November and December. Spring tides plus a sirocco wind make the worst days.

The city's tide forecasting centre, the Centro Previsioni e Segnalazioni Maree, measures every tide against the reference zero at Punta della Salute. Normal tides swing well below any pavement. Autumn storms push water into the lagoon from the Adriatic, and when that lines up with a full or new moon, the sea comes up through the drains.

The record is 187 cm on 12 November 2019, before MOSE worked. Winter 2026 was busy in a new way: the barriers were raised 18 times between 28 January and 11 February, which Alvise Papa of the tide centre called entirely unusual, according to Il Post. In his words, twenty years ago it took a run of bad weather to flood the city, "oggi bastano precipitazioni anche modeste".

How high is the Rialto area, and when does it flood?

Low. The Erbaria, the waterfront by the market, goes under at tides of 75 to 80 cm, about the same as St Mark's Square.

Il Post puts it bluntly: a tide above 75-80 cm is enough to put "la zona dei locali vicina al ponte di Rialto (l'Erbaria) e piazza san Marco" under water. The Erbaria is the strip of bars and stalls along the Grand Canal on the San Polo side, right where the market meets the bridge. The fish market behind it and the Riva del Vin sit on the same low ground. The bridge itself is high and dry: the ramps climb well above any tide.

For the rest of the city, the tide centre publishes how much of the pedestrian network floods at each level. At 100 cm about 5% of walkways are wet. At 120 cm it is close to 29%, and at 140 cm more than half, according to the centre's figures as summarised on Wikipedia. Rialto is in the first few percent.

Does MOSE stop acqua alta at Rialto?

It stops big floods, not small ones. The protocol aims to keep the city below 110 cm, so tides of 80 to 105 cm still wet the Erbaria.

The rule, as Il Post reports it: MOSE is raised to stop the tide in the city reaching 110 cm, and because forecasts can miss by about ten centimetres, it goes up when the forecast says 101 cm or more. Each raising costs around EUR 200,000. Below that line, the barriers stay on the seabed and the low parts of Venice flood as they always have.

In practice: a 90 cm morning in November means water at the Erbaria and in St Mark's Square, while most of the city stays dry. Plan your market visit for later in the morning on those days, after the peak has passed. Floods usually drain within two or three hours.

How do you check the tide forecast and read the sirens?

The tide centre publishes forecasts online, and sirens sound a few hours before tides of 110 cm or more, with one to four rising tones for the expected height.

The Comune's tide page carries the forecast for the next days, the live level and alerts. When a tide of 110 cm or more is expected, sirens across the city sound about three hours ahead. The first sound is a general warning. The second tells you how high: one tone for over 110 cm, two for over 120 cm, three for over 130 cm and four for over 140 cm, per the description on Wikipedia.

With MOSE in service, the sirens are less common than they were. A 90 cm tide does not set them off, and that is the level that matters at Rialto. Check the forecast the evening before.

Do you need rubber boots, and where are the passerelle?

Ankle-high water is common at Rialto in a flood, so waterproof boots help. The city lays raised walkways on main routes, but not always.

The passerelle are trestle walkways set up on key routes when a high tide is due. They are narrow and slow, one person wide in places, and on crowded days they back up. During Carnival 2026 the service was suspended in many areas because of the crowds, Il Post reported. Do not count on them.

Simple plastic overboots are sold in shops and kiosks across the centre on flood days. Proper rubber boots are better if you are staying a week in November. Wait it out with a coffee if you can: the water is gone a few hours later, and the bacari by the market open again as soon as it drains. Our guide to cicchetti bars near Rialto lists the classic ones.

Which Rialto tours cancel in high water?

Four listings name high tide: the San Marco to Rialto walk, the San Marco shared gondola, the Piazzale Roma private gondola and the cicchetti walk's traghetto.

From the listings on Viator, checked 22 October 2026:

• The San Marco to Rialto walking tour does not run in exceptional high tide. It moves to the next day or you get a refund.
• The shared gondola from San Moisè does not run in exceptionally bad weather or high or low tide, with the same postpone-or-refund rule.
• The private gondola from Piazzale Roma may be cancelled by the supplier in exceptional high tide or heavy rain, with a full refund.
• The cicchetti and wine walk skips its traghetto crossing in bad weather or high water. The guide walks you round instead and the food stops stay the same.

The Rialto Market lunch states it takes place rain or shine. Read the fine print on boats: the motorboat tour says weather cancellations by the boat operator are not refunded. A guest of the Rialto gondola wrote in 2023 that gondolas were not running in rain and wind, and the refund was refused because the booking had not been cancelled 24 hours ahead. Our rule for November: check the tide forecast two days out, and use the free 24-hour cancellation if it looks high. More on rides in our gondola price guide.

A long market lunch with wine at every stop, starting at San Giacomo di Rialto. It runs whatever the weather does.

★ 4.9 · 4 hours · from $108

Explore the Rialto Market lunch tour → Tour details

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