A clear, practical and authentic guide created by TripVenice to help visitors understand one of Venice’s most unique natural events.
🟦 What Is Acqua Alta?
Acqua alta literally means “high water.”
It happens when tide, wind and atmospheric pressure combine to raise the water level inside the Venetian lagoon.
It is not a dangerous event, and it does not flood the whole city.
Most of the time it lasts 1–3 hours, and Venice returns to normal immediately afterward.
Today, thanks to the MOSE barriers, acqua alta is much rarer than in the past.
🗓️ When Does Acqua Alta Happen?
Acqua alta is most common during:
Autumn (October–November)
Winter (December–January)
During the rest of the year it can still occur, but it’s usually mild and limited to a few low-lying areas.
📏 How High Does the Water Rise?
Venice uses a tide measurement system in centimeters (“centimetri”) from the Punta della Salute tide station.
Here’s how to understand the numbers tourists often see:
Tide Level Name What It Means for Visitors
+80 cm High tide Mostly invisible, only small puddles
+100 cm Significant St. Mark’s Square gets wet
+120 cm Very high Raised walkways appear
+140 cm Exceptional Rare, limited access in some zones
Only 5% of the city is lower than +100 cm.
⚙️ How MOSE Protects Venice
Since 2020, Venice has been protected by MOSE, a system of yellow underwater barriers placed at the three lagoon inlets (Lido, Malamocco, Chioggia).
When the tide is forecast to exceed a certain level, the barriers rise and isolate the lagoon from the sea.
Thanks to MOSE:
St. Mark’s Square stays dry most of the year
extreme floods are now extremely rare
tourists experience acqua alta far less frequently
But Venetians, especially those living on ground floors, still use local flood barriers.
🪵 Real Venetian Flood Protection: The “Super Mose”
This doorway shows a typical wooden flood barrier used in many Venetian homes at street level.
Every resident builds their own version to stop small tides from entering the house.
In this case, someone wrote “SUPER MOSE” on the panel as a joke — a playful reference to the large MOSE barriers that protect Venice from major high tides.
These DIY barriers are:
simple but effective
installed manually
unique in every house
part of real everyday Venetian life
Visitors often walk past them without noticing, but for locals they’re essential during seasonal tides.
🌍 Which Areas Flood First?
These spots are the most sensitive during higher tides:
St. Mark’s Square (Piazza San Marco)
The lowest point in Venice: first area to get wet.
Rialto Area
Some calli near the Grand Canal may accumulate water.
Cannaregio
Fondamenta della Misericordia and nearby alleys.
Castello (San Zaccaria zone)
Some narrow passages near the waterfront.
Santa Croce & San Polo
Only in exceptional tides.
Murano, Burano, Lido, Giudecca → generally less affected.
👣 What Actually Happens During Acqua Alta?
Venice remains completely safe and functional.
Visitors will see:
✔ Locals wearing waterproof boots
Boots are sold everywhere during autumn — even in supermarkets.
✔ Raised walkways (“passerelle”)
They guide people across the lowest flooded sections.
✔ Shining reflections on stones and canals
A dream for photographers.
✔ Shops and restaurants open as usual
Only very narrow alleys might temporarily close.
✔ The tide slowly goes down
The water recedes naturally after a few hours.
🚤 How to Check the Tide in Real Time
Venice has a very accurate tide monitoring system.
Best app (100% recommended):
📱 Hi!Tide Venice
Shows tide levels, maps, real-time alerts and forecast by area.
Also useful:
“Centro Previsioni e Segnalazioni Maree” (municipal website)
Tide tables posted on ACTV ferry stations
Google “Venice tide forecast” → automatic data from Punta della Salute
🧳 Tips for Visitors During Acqua Alta
✔ Bring waterproof shoes (in autumn)
Even inexpensive lightweight boots are enough.
✔ Stay on raised walkways
They guide you safely.
✔ Don’t worry about transportation
Vaporetto service stays active.
✔ Keep an eye on narrow, low alleys
They may temporarily flood.
✔ Enjoy the moment
Acqua alta is part of Venice’s identity — and a rare experience.
📸 Photography Tips: Acqua Alta Edition
Acqua alta produces some of the most beautiful scenes in Venice:
reflections of palaces on wet stones
St. Mark’s Basilica glowing at night
empty alleys with shimmering water
colorful boots everywhere
The best time for photography is:
🌅 sunrise and 🌇 sunset during a mild tide (+90/+105).
❓ Frequently Asked Questions
No. The tide rises slowly and Venice is designed for it.
Usually 1–3 hours.
No. Only low areas get wet, and mostly for a short time.
It stops major events. Minor tides (+80/+100) can still appear in some alleys.
Absolutely not. It’s easy to manage and very unique to see.
Hotels are equipped and usually located above flood-prone areas.
🏁 Conclusion
Acqua alta is not a problem —
it’s a beautiful, photogenic and very Venetian experience.
With MOSE, Venice is safer than ever, and acqua alta has become a rare and fascinating event for visitors.
TripVenice helps you enjoy it like a local.
See also: