I was in there in the middle of May and although I don’t personally remember how warm the water was, there were plenty of people sunbathing and swimming so I’d say it was probably fine. Most people stay/start in Monterosso which also has the best beach in CT. The next town (Vernazza) also has a nice little beach and its a good relax after the 2hour hike from Monterosso. If I remember correctly, those were the only towns with sand beaches in CT.

We arrived in Vernazza last year on June 1 and the weather was nice and warm – actually pretty hot when you got to hiking. But the water was cold as ice. We went deep water swimming in Manarola and swam at the beach in Monterrosso, but I couldn’t stay in but a minute or two before turning blue. It was refreshing, but it doesn’t take me long to swim in cold water. Our favorite activity in that area, in addition to hiking parts of the trail, was to rent a motorboat at the harbor in Vernazza. It cost 35 euros plus another 7 for gas. We had the boat all by ourselves for 2 hours, which was plenty of time to cruise up and down the coastline by all 5 towns, explore some of the grotto areas on the rocky coastline and get in a little topless sunbathing out of public view. By the way, the hiking is easier if you start in Riomaggiore and work your way toward Monterrosso – less uphill.