Hi, Uttarakhand can be visited throughout the year except for the peak monsoon season in July and August. Uttarakhand is an ever embracing state, but summer is the best time to visit this state when the temperature is cold and pleasant. July and August must be avoided as the state receives high rainfall during these months making it wet and damp. Winters are icy, and some parts of the state also experience snowfalls during this period making it even more picturesque and beautiful. I have also attached best places for you to visit in Utarakhand to help you plan your trip better. Please check it out here- https://www.tripoto.com/trip/best-hill-stations-in-uttarakhand