Italy has 1,500 lakes. Some are glacial (cold, crystal, surrounded by Dolomites). Some are volcanic (warm, crater-shaped, surrounded by forests). Some are Mediterranean (mild, large, with beach towns). All are swimmable — but the difference between a 14°C Alpine plunge and a 26°C volcanic bath is the difference between screaming and sighing. This guide ranks 15 lakes by swim-ability.
1. Lago di Bolsena (Lazio): Italy's largest volcanic lake. Clean, warm (24-26°C July-August), sandy beaches, uncrowded. The best lake swimming near Rome (1.5h). Medieval Bolsena town. FREE public beaches. 2. Lago di Bracciano (Lazio): Another volcanic lake — closer to Rome (50 min), clean, warm. Anguillara Sabazia beach (free, sandy). 3. Lago Trasimeno (Umbria): Large, shallow, warm — Italy's 4th-largest lake. Castiglione del Lago has public beaches. 4. Lago d'Iseo (Lombardy): Warm, less famous than Como/Garda, Monte Isola (the largest lake island in Europe — ferry, beaches, cyclists).
5. Lake Garda (south/east shore): The south is warm enough for comfortable swimming (22-24°C). Sirmione beach (Jamaica Beach — flat rocks, crystal water). Lazise, Bardolino — gravel beaches, clean. North (Riva/Torbole): Cooler (18-20°C), better for windsurfing. 6. Lake Como: Warning: colder than expected (18-22°C). Deep, glacial. Best swimming: Lido di Bellagio (€7, pool+lake), Varenna's swimming area. Go in July-August ONLY for comfortable swimming. 7. Lake Maggiore (west shore): 20-23°C summer. Lidos at Stresa, Cannobio (one of Italy's most beautiful lakeside villages — sandy beach, market Saturday).
8. Lago di Braies (Dolomites): Emerald green, 14-16°C even in August. NOT for swimming laps — for a dramatic plunge + immediate exit + Instagram triumph. 9. Lago di Tenno (Trentino): Turquoise water, tiny island, 16-18°C. A hidden gem above Lake Garda. 10. Lago di Carezza (Dolomites): The "rainbow lake" — too cold and too small for swimming but the COLORS (reflections of the Latemar peaks) justify the detour. 11. Lago di Tovel (Trentino): Once turned RED from algae (no longer) — now emerald, cold, alpine. 12. Lago di Scanno (Abruzzo): Heart-shaped from above, warm enough for swimming (20-22°C), mountain village above.
13. Cascate di Chia (Viterbo, Lazio): Natural waterfall pools in a forest — warm, deep, FREE. 1.5h from Rome. 14. Gole dell'Alcantara (Sicily): Swim through a volcanic basalt gorge — cold (15°C) but EXTRAORDINARY. €13 entry. 15. Cascate del Mulino (Saturnia, Tuscany): Not a lake but 37°C thermal cascades — the most COMFORTABLE "wild swimming" in Italy. Free. 24/7.