Palawan is an ecological island unlike most of the Philippines, in that it adheres to a very strict ecological governing and lifestyle that not only preserves the natural beauty but also displays the local government and its population how nature can be preserved without compromise. There is an absolute balance that lends to the attraction of the region and what it has to offer to both locals and tourists alike.
Since it is in the tropics, you're pretty much guaranteed heat. Just want to check for typhoon season to be safe though. I'm not sure if it's in the typhoon belt or alley. It has accommodations for all levels, from budget to luxury (Dos Palmas Resort).
The Puerto-Princesa Subterranean River National Park, Coron Reefs, Coron Bay, and Busuanga, El Nido Marine Reserve Park are internationally known attractions to see. June is a good month with July leading into the rainy season for the northern part of Palawan.