Kashmir changes character with every season, so the best time depends on what you want to see.
Spring (March to May)
Tulip gardens bloom in Srinagar and the valley turns green.
Summer (June to August)
Pleasant weather for Pahalgam, Sonamarg and long days outdoors.
Autumn (September to November)
Chinar trees turn gold and red, and crowds are thinner.
Winter (December to February)
Snow in Gulmarg for skiing and gondola rides. Pack proper warm layers.