Hi Smit, Spiti Valley temperature in August varies from 15° Celsius to 4° Celsius, and contrary to the popular opinion, it seldom rains. So, don't let yourself fall for the myth because while a lot of other places receive heavy downpour during this month, Spiti usually doesn't. Attached below are few packages offered by Tripoto for hassle free travelling. Please take a look, fill the form and someone will get in touch with you. Thanks!
August is the monsoon months when monsoon is in full swing in Kinnaur and it is better to avoid this time as the area is prone to landslides. However, Spiti valley itself remains fine at this time. follow the link below to get full info.
https://www.indianholiday.com/spiti/best-time-to-visit-spiti.html
Spiti, like Ladakh, is a dry cold desert that sees close to no rains, even during the monsoon season. However, the approach roads from the Shimla side see quite a bit of rain leading to patchy road conditions. You will also need to cross some water crossings especially at the stretch between Batal and Gramphoo.
The valley shrouds itself in beautiful autumn colours of brown and burnt orange, that make the place even more stunning. The days are pleasant and the nights cool, perfect to enjoy the charm of the valley.
Duration of monsoon: Months of July till September are considered to be the monsoon months in Spiti.
Average temperature: The average temperatures range between 10°C (daytime) to 4°C (night).
During the months of July to September, Spiti is accessible both from Manali and Shimla routes.
The Shimla route passes through Narkanda – Rampur – Kalpa - Nako-Giu Village - Tabo Village – Dhankar - Pin Valley (Mud Village) – Kaza
From Manali side, the route that you will need to take will pass through Solang Valley – Rohtang Pass – Gramphu – Batal – Chandratal – Kunzum Pass – Losar – Kaza