The best time to be on this island is during the European winter, especially the time between December and mid March will never leave you disappointed (a 80kg rider with 9m and 12m kite can kite >80% of the days). If you are a regular user of windguru it can be said that it works very reliably for this island (the same accounts for the wind statistics), but as the wind in warmer regions is less dense you have to subtract around 2-3 knots from the windguru prediction to obtain the windspeeds you might be used to in colder regions, but no worries the wind is still enough.
The strongest breeze usually comes in the morning, reliably starting around 9am, so if you are here purely for the kiting, skip the party night out and make your way early to the beach. The late risers don't need to be worried, the wind usually blows until the sun goes down, but usually takes a bit of a blip during midday and picks up again in the later afternoon (around 2-3pm).
The best kite sizes to bring for heavy riders 80-90kg are 8-10m for the stronger days and 10-14m for the weaker days, lightweight girls can easily subtract 2m of the above.
80kg rider with 12m kite: