Hi Paty
May is usually lovely during the day and hot (temperature well up in the 80s) definitely bikini weather and you'll get a good sun tan, but the nights can be chilly, especially if the wind's blowing off the sea, so best to take a cardigan or light jacket.... or just treat yourself to a pashmina when you arrive
You'll have to be brave to get in the sea though.... that'll be freezing!
When in May are you going and where are you staying? I'm going on the 14th for a week staying at the Lighthouse apartments.
Mazz