July to September in the 70's-90's°F and kitable for about 5 months. Always bring a wetsuit but you will be fine when it's warm. The water warms up really warm in late June and stays warm till mid to late October but you can still kite with a wetsuit an extra two months.
Take a plane to McArthur. You drive east to Greenport or take a train. The train gets off right their, the jetty stretches out several hundred feet almost touching Shelter Island. Take a boat or walk from the train in green port by the fairy east and ask where the jetty is theres a lot of fisherman, they are nice though.
