The ideal period to plan a visit to Panchavati in Nashik is between October and March, when the climate is most pleasant. During these months, the weather in Nashik is moderately cool, with temperatures ranging from a comfortable 10°C to a maximum of around 30°C. This allows for a more comfortable exploration of the various religious sites and the picturesque surroundings without the intense heat that characterizes the summer months. The famous Kumbh Mela, a massive Hindu pilgrimage, also takes place in Nashik every twelve years during this period, which can be a fascinating event to witness, although it tends to draw massive crowds leading to a very crowded experience.
If you are interested in attending the annual celebrations associated with the Godavari River, you might consider planning your visit during the festivals of Makar Sankranti in January or Shivratri which usually falls in February or March. Visiting during these events will offer a unique cultural experience as you observe the traditional rituals and partake in the festivities. However, it's worth noting that these are also popular times for tourists and pilgrims, so accommodations might be more difficult to find and prices could be higher due to the increased demand.