Due to its topography, the best time to visit Peru varies. The majority of the country can be visited all year round. However, winter (from April to September) is the ideal time to visit the Andes and to trek the Inca trail, as the weather is at its driest. June also hosts the Inti Raymi festival in Cuzco, a theatrical festival based on an ancient Incan ceremony. The Peruvian Amazon is hot, humid and wet throughout the year, though August tends to have fewer mosquitoes.
Meanwhile, visiting the Andes during its ‘green season’ from November to March has its advantages, with fewer visitors to compete with, and a lush environment fed by the rains.
If you are wanting to trek the Inca Trail, please be aware it is closed the entire month of February for conservation purposes.