There are two main seasons making Kashmir as best time to visit. One is November to February - you would find snow and snow. Other is March to May- called as warm period where u get to see lot of scenic spots, picturesque views.
Autumn is the best season to visit kashmir, everywhere the red falling leaves of Chinar, popular trees are seen. In this season you can visit Different Chinar gardens of Kashmir and you can witness the beauty of autumn there.