The best time to visit Tiwanaku is during the dry season, which runs from May to October.
During these months, you'll experience clear skies and cooler, more comfortable temperatures, making it ideal for exploring the extensive archaeological site. The dry conditions mean less mud and easier walking across the ancient ruins, including the Akapana Pyramid and the Kalasasaya Temple.
For those looking for a truly great experience, visiting around the Winter Solstice (June 21st) is particularly special. This is when the Aymara New Year (Machaq Mara) is celebrated at Tiwanaku, attracting many visitors and offering a glimpse into indigenous traditions. However, it can be crowded during this period, so booking accommodation and transport well in advance is essential if you plan to attend.