A thin wetsuit is recommended. The air in summer is around 25-32°C.
Beach and Tide Conditions
Kitesurfing conditions do not depend on Tide on this spot. Rovinj, Croatia is a Flat, Chop and Small waves spot. The launching/landing area is reported to be of Small size. Directly in Roving and around there are no sandy beaches. Mostly small stones and rocks. Hard sand next to shore. You can forget self-launching of kites. There is no tide and the water is generally choppy. According to the weather there can be waves up to 1-2 meters but its generally not so. There are also many days where the water is also calm and flat, but only in light wind days.
Need to know
The is no particular rules reported , but as a best practice, talk to a local before you go on water.