Best time to visit Rasol is in either Winter season ( November to February) or Spring season ( April to September). while in winter you get to witness the grey atmosphere and snow clad mountains whereas in Spring, you witness the true lush green nature of Rasol. both are serene and depends on the preference.
Best time to visit rasol is February because weather is quite good not so cold not so hot...moderate temperature..
and if you like snow you should visit in December or January
Rashol (3,048 m) is a small town high in the Parvati Valley highlands that provides for an immensely relaxing trip in Himachal Pradesh's Kullu district. The ideal months to go on the Rashol hike are April to December.
Rasol is a magical village in the Parvati Valley. it is close to famous places like Kasol and Malana Village.
You have to trek for 30-40 mins from Kasol to reach Chalal and from Chalal you can trek to Rasol duration is 3-4 hours.
Best time is from April to December