Determining the best time to visit Peru depends largely on the regions you plan to explore, as the weather varies considerably across the country. The most popular period for travelers is during the dry season, which spans from May to September. This period is ideal for trekking adventures, including the famed Inca Trail to Machu Picchu, as clear, sunny days provide optimal viewing conditions. If you're keen on visiting the coastal regions, such as Lima and the surfing havens up north, consider the months of December through March. The weather is warm and beach-friendly, contrasting with the cooler, overcast conditions in the off-peak months. For the Amazon rainforest, there isn't a huge variation in climate throughout the year. It's generally hot and humid with frequent rainfall. The so-called drier season, from May to September, may provide the most comfortable conditions for a jungle expedition.