# Lake Maggiore: 212.5 km2, 370 m at its deepest

> Lake Maggiore is second in Italy by surface and volume and 370 m deep, and its winter mixing has stopped above 100 m for ten years in a row.

URL: https://myitalia.it/nature/lago-maggiore
Last updated: 2026-09-02

Lake Maggiore covers 212.5 square kilometers and reaches 370 meters deep, which makes it the second Italian lake by both surface and volume, behind Garda in area and behind Como in depth.

## The numbers, and where they disagree

Lake Maggiore, the Verbano, has a surface of 212.5 square kilometers, a maximum depth of 370 meters, a mean depth of 176 meters and a volume of 37.5 cubic kilometers. Its level is regulated by the Miorina dam at Sesto Calende, the Ticino and the Toce flow in, and the Ticino flows out.

Two things are worth knowing about those figures. The two CIPAIS pages give 212 and 212.5 square kilometers, and the more detailed factsheet is the one quoted here. And the elevation of the lake surface above sea level is not published by CIPAIS at all, so this page does not state one.

Depth ranks the prealpine lakes cleanly: Como 410 meters, Maggiore 370, Garda 350, Iseo 251. Even there a discrepancy hides. The Garda factsheet gives 346 meters where the comparative table gives 350, two institutional numbers for one lake bottom.

## A basin shared with Switzerland

The catchment of Lake Maggiore covers 6,599 square kilometers, split between Italy with 3,229 and Switzerland with 3,370, yet 80% of the lake surface itself lies in Italian territory.

Around 670,000 people live in the basin and it records 12 million tourist overnight stays a year, both declared by CIPAIS as orders of magnitude rather than counts.

The cross border shape has a practical consequence. Water quality, level regulation and fishing rules here are decided by an Italo-Swiss commission, which is why the institutional data on this lake is unusually good and unusually hard to reconcile between pages.

## The winter mixing has failed for ten years

In 2023 the winter overturn of Lake Maggiore stopped at 60 meters of depth, the tenth consecutive year in which it stayed within the top 100 meters, and oxygen in the deep water hit the lowest values in the historical series.

That sentence is the measured signature of warming on a deep lake. A lake this size normally turns over in winter, carrying oxygen down and nutrients up; when the surface no longer cools enough to sink, the bottom stops being renewed.

Ten consecutive years is not weather. It is the reason the deep water oxygen minimum is a record rather than a fluctuation, and the figure should be rechecked against the next annual monitoring report.

## The Borromean Islands are shut all winter

The Borromean Islands open on a season, and in 2026 that season ran from March 12 to November 8, with last entry at 5:00 pm until October 24 and 4:00 pm from October 25 to November 8.

From mid November to early March they are closed. This is the most useful fact about them and the one most often missing from guides, which describe the palace and the gardens as though they were available on any date you happen to choose.

Isola Bella alone costs €27.00 for adults and €18.00 for ages 6 to 15 in 2026. Isola Bella with Isola Madre is €40.00, and the combination with the Parco Pallavicino €55.00. Under 2s are always free, 3 to 5 year olds free on single tickets, and the boat to the islands is a separate purchase. See [Italian lakes](/themes/lakes) and [Piedmont](/regions/piemonte).

## FAQ

### How deep is Lake Maggiore?

370 meters at its deepest and 176 meters on average, over a surface of 212.5 square kilometers and a volume of 37.5 cubic kilometers. Among the large prealpine lakes only Como is deeper, at 410 meters.

### Which Italian lake is the deepest?

Como, at 410 meters, ahead of Maggiore at 370 and Garda at 350 on the same institutional comparison; Iseo follows at 251. The detailed Garda factsheet gives 346 meters instead, so two official sources disagree on that one lake.

### Is Lake Maggiore in Italy or Switzerland?

Both. Its catchment covers 6,599 square kilometers, 3,229 in Italy and 3,370 in Switzerland, but 80% of the lake surface itself is Italian. Around 670,000 people live in the basin, which records 12 million tourist overnight stays a year.

### When are the Borromean Islands open?

In 2026 from March 12 to November 8, with last entry at 5:00 pm until October 24 and 4:00 pm after that. From mid November to early March they are closed, which is the single most useful fact about them and the one guides leave out.

### How much is Isola Bella?

€27.00 for adults and €18.00 for ages 6 to 15 in 2026. Isola Bella with Isola Madre is €40.00, and adding the Parco Pallavicino brings it to €55.00. Under 2s are always free and 3 to 5 year olds free on single tickets. The ferry is charged separately.

## Sources

| Fact | Source | Confidence | Valid until |
|---|---|---|---|
| Il Lago Maggiore (Verbano) ha una superficie di 212,5 chilometri quadrati, una profondita' massima di 370 metri e una profondita' media di 176 metri, con un volume di 37,5 chilometri cubi: e' il secondo lago italiano sia per superficie sia per volume. Il livello e' regolato dalla diga della Miorina a Sesto Calende. | [CIPAIS - Commissione Internazionale per la Protezione delle Acque Italo-Svizzere](https://www.cipais.org/web/lago-maggiore/il-lago); [CIPAIS](https://www.cipais.org/) | medium | 2099-12-31 |
| Tra i grandi laghi prealpini il Lago di Como e' il piu' profondo con 410 m, davanti al Maggiore (370 m) e al Garda (350 m). | [Osservatorio dei Laghi Lombardi - Regione Lombardia, Fondazione Lombardia per l Ambiente, ARPA Lombardia, CNR-IRSA](https://fondazionefla.it/wp-content/uploads/2021/07/Qualita-acque-lacustri-in-Lombardia.pdf) | medium | 2030-12-31 |
| Il bacino imbrifero del Lago Maggiore copre 6.599 km2 divisi fra Italia (3.229 km2) e Svizzera (3.370 km2), ma l'80% della superficie del lago e' in territorio italiano. | [CIPAIS - Pannello di Controllo del Lago Maggiore 2023](https://www.cipais.org/web/wp-content/uploads/2025/01/CIPAIS_PdC_Lago_Maggiore_2023.pdf) | medium | 2028-12-31 |
| Nel 2023 il rimescolamento invernale del Lago Maggiore si e' fermato a 60 metri di profondita', restando per il decimo anno consecutivo entro i 100 metri, e l'ossigeno nelle acque di fondo ha toccato i minimi assoluti della serie storica. | [CIPAIS - Pannello di Controllo del Lago Maggiore 2023](https://www.cipais.org/web/wp-content/uploads/2025/01/CIPAIS_PdC_Lago_Maggiore_2023.pdf) | medium | 2027-06-30 |
| Le Isole Borromee sul Lago Maggiore sono visitabili solo in stagione: nel 2026 dal 12 marzo all'8 novembre, con ultimo ingresso alle 17.00 fino al 24 ottobre e alle 16.00 nell'ultimo tratto di stagione; l'ingresso alla sola Isola Bella costa 27 euro per gli adulti e 18 euro per i ragazzi 6-15 anni, il combinato Isola Bella + Isola Madre 40 euro. | [Terre Borromeo](https://terreborromeo.it/en/isola-bella/hours-prices) | medium | 2027-03-31 |

## Image

https://media.myitalia.it/media/nature.lago-maggiore.v2.1600.jpg
Author: Isiwal. License: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0).
Source: https://commons.wikimedia.org/wiki/File:Lago_Maggiore_Isola_Superiore_from_Isola_Bella.jpg

## Other languages

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