Weather
Bright, sunny weather continues for the most part in the Sacred Valley this month, with little rain and temperatures highs of around 68° F (20° C) and lows around 36° F (2° C). Nights and early mornings can still be nippy however: pack warm clothes accordingly. Down in the jungle below Machu Picchu, water levels are low: good for spotting wildlife on river banks.
Crowds & Costs
Crowds are still considerable in and around Machu Picchu, as are costs for hotels and most activities. This is, after all, peak holiday season for North Americans and Europeans, although overall tourist levels are perhaps slightly down on June, the busiest month.
Chat with a local specialist who can help organize your trip.
Where to Go
Sunny weather and crowds in Cusco may incline you towards spending more time out in the countryside, thereby avoiding the masses. There are many incredible ruins in the Sacred Valley, such as the concentric circular terraces of Moray near Maras, or the steep terraces of the Ollantaytambo ruins marking the point where the Spanish conquistadors lost one of their few battles against the Inca. You will have needed to reserve your spot on the Inca Trail many months in advance to be able to hike it this month, but there are plenty of lesser-known hikes in this part of the Andes: see this article on the best day hikes in the Sacred Valley for ways to escape the crowds.
What to Do
Trekking is definitely the most popular activity in the Sacred Valley - and is a surefire bet to evade the most touristy parts of the Sacred Valley if you dislike being amongst crowds. It is definitely appealing, seeing as the jungle is relatively close and August is one of the best times of year to visit it, to spend some time here too. You could try the Inca Jungle Trek, which gives tourists a jungle experience before taking them to Machu Picchu on the final day.
August Events
August is quieter after the Andean mega-festivals that enlivened the region in June and July.
Pachamama Raymi: Earth mother day, or the day in honor of the Incan Mother Earth, Pachamama, happens on August 1. There are celebrations of this traditional Andean festival throughout the Sacred Valley - including, evocatively, at the ruins of Moray.
Willka Raymi: on August 31, this is another honoring of Pachamama, this time in Pisac where particular thanks are also given to the condor as well as to Pachamama. The event is wrapped up with traditional music and feasting.
More Helpful Information
Machu Picchu in July
Machu Picchu in September
Ultimate Guide to Machu Picchu
Peru in August