It is not mandatory, however, a guide ensures your safety. They can recognize, avoid, and treat high-altitude illnesses. They also have mountain experience and know every route. Furthermore, they can provide an interesting insight into the local culture, history, and religious beliefs and practices.

Yes, depending on your current fitness level.

The ideal months to go for a Himalayan trek are late October until early May, depending on the exact location and altitude of the trek. This is due to the annual monsoon season that brings not ideal weather condition.

Har Ki Dun - In summers visit between April-June for pleasant weather conditions.
If you're interested in snow, winter (September-December) would be the best time to visit this trek.

Kunjapuri Trek - Mid Sept to Mid April, for the best weather conditions. An early morning start is recommended to catch the sunrise.

Dasrath Ka Danda - April to June and Mid- September to March. If you wish to catch the Hariyali puja at the Pavki Devi temple, December/January would be the best months to visit as it is the Pausha month according to the Hindu calendar.

The different options cater to various difficulty levels due to the differences in altitude and duration.

Har Ki dun: Altitude - 11,811 ft.; Duration - 7 days; Difficulty - Moderate
Kunjapuri Trek: Altitude - 5396 ft.; Duration - 6 hrs; Difficulty - Easy
Dasrath Ka danda: Altitude - 4750 ft.; Duration - 2 days; Difficulty - Easy

There are a multitude of activities in the Rishikesh area. They range from river rafting for all experience levels, bungee jumping for all adrenaline junkies out there and a whole treasure trove for trekking-enthusiasts. Trekking through the jungle and nature trails is undoubtedly one of the best things to do in Rishikesh. Try to avoid the above-mentioned activities during the monsoon season.