We arrived in Kos 30th April 2003, the weather was beautiful for the whole week. Be very careful of the breeze though as it gives you the impression that the suns not that hot and as a result my Partner ended up with sunstroke. The is only one real down point to coming to Kos so early on in the season and that is the majority of the trips are not yet running due to the lack of demand. We discovered that most of the trips actually start the 2nd week in May. I would say that early May is an ideal time for young children as it's not too hot or busy.