The locals head to their local Lido to escape the heat. Even though a few have a spit of sand, you will mostly find a nice lake side pool, a restaurant, bathroom/dressing facilities with umbrellas and lounge chairs for rent. Almost every town has one.
Lido di Cernobbio
Piazza Risorgimento 5
Gorgeous views of the lake of course, but also Villa Erba right next door. The lido has a baby pool and a large, adult pool. The restaurant has excellent pizza. Get there early on Summer weekends for a spot! Opens at 9:00am, until 7:00pm. LidodiCernobbio.com
Lido Villa Olmo
Via per Cernobbio, 2
This one is big, with two swimming pools and a natural little beach. They have parking, which is a huge plus, but get there early. Opens at 9:00am, until 7:00pm. LidoVillaOlmo.it
Lido di Moltrasio
Via Regina 27A
This lido boasts a two-tiered diving platform into the lake and a buzzing restaurant. It is right near the Grand hotel Imperiali in Moltrasio. No pool! but a lake side area with umbrellas & lounge chairs to rent for the day.
Lido di Lenno
Via Comoedia, 1
Tremezzina / Lenno
Lido di Lenno also has sand and is near Villa Balbianello, one of my favorite lake "To Do's. This is were you would get on board a small shuttle boat to take you over to the villa for a tour. There's a restaurant, facilities, umbrellas & lounge chairs for rent. lidodilenno.com