Four seas
Swiss glacier meltwater reaches four seas: the Rhine carries it to the North Sea, the Rhône to the Mediterranean, the Po to the Adriatic and the Inn, by way of the Danube, to the Black Sea.
Where the meltwater goes
| River | Sea | Glaciers | Area 2016 | Share | Since 1850 | 2100 · SSP2-4.5 | Peak water |
|---|---|---|---|---|---|---|---|
| Rhine | North Sea | 639 | 295.4 km² | 31% | −47% | 24.2 km² | 2020 |
| Rhône | Mediterranean | 570 | 582.1 km² | 61% | −35% | 93.7 km² | 2023 |
| Po | Adriatic | 84 | 34.8 km² | 4% | −59% | 1.4 km² | 2020 |
| Inn | Black Sea | 107 | 49.0 km² | 5% | −57% | 6.7 km² | 2020 |
Peak water: the year the glaciers’ combined meltwater is highest (11-year mean, OGGM median, SSP2-4.5).
Glaciers by river
Meltwater by river
Million m³ of water per year from each river’s glaciers, 11-year mean, four scenarios.
Rhine → North Sea
639 glaciers, 295 km² in 2016. Sub-basins: Upper Aare, Reuss, Kander & Simme, Alpine Rhine, Linth, Saane, Thur.
Rhône → Mediterranean
570 glaciers, 582 km² in 2016. Sub-basins: Vispa, Lötschental–Aletsch, Dranse, Goms, Hérens & Nendaz, Anniviers & Turtmann, Trient & Chablais, Diablerets–Wildhorn, Vaud Alps.
Po → Adriatic
84 glaciers, 35 km² in 2016. Sub-basins: Mera, Diveria, Poschiavino, Maggia, Brenno, Ticino, Moesa.
Inn → Black Sea
107 glaciers, 49 km² in 2016.
Sources
- Linsbauer et al. (2021). The new Swiss Glacier Inventory SGI2016. Frontiers in Earth Science 9. doi.org/10.3389/feart.2021.704189
- Zekollari et al. (2024). Twenty-first century global glacier evolution under CMIP6 scenarios and the role of glacier-specific observations. The Cryosphere 18 (OGGM v1.6 projections). tc.copernicus.org/articles/18/5045/2024/
- Huss, Linsbauer & Naegeli (2025). Swiss Glaciers. State, projections and significance. Swiss Academies Factsheets 20(2). doi.org/10.5281/zenodo.14866776