The Inca Trail cross four ecozones with distinct microclimates. The trail begins at the Quechua zone (2300-3500 m; 7,546-11,483 ft) whose microclimate is dry and temperate, which is ideal for the agriculture.
The next ecozone is Suni or Jalca, located at 3500-4000 m; 11,483 -13,123 ft above sea level. Some agriculture is still possible at this altitude. Above the Suni/Jalca zone is the Puna (4000 – 4800 m; 13,000 – 15, 750 ft). The Puna comprises mostly grassland since the weather is cold and frosty. The Ichu (grass) is consumer by grazing Andean camelids.
The descent from the Puno into the Suni zone traverses Fluvial Yungas (transitional zones between Andean highlands and eastern slope forests at 1000 – 2300 m (7,500 -3,300 ft), which are characterized by a neotropic climate: rainy, humid and warm. The word “yunga” means warm valley in Quechua.
The weather in the Andes and the Sacred Valley is characterized by warm sunny days and very cold nights. Cloudy conditions can cause daytime temperatures to drop and it’s best to dress in layers that you can easily add or remove as necessary.
The wet season runs from November to March. Drizzle is likely, the nights are warmer, and the trail can get muddy. However, the rainy season is the perfect time to appreciate breathtaking views of mist-covered mountains and enjoy the region’s diverse flora in full bloom.
The dry season between June and August sees much less cloud cover and the panoramic views of surrounding snow- and glacier-capped mountains are simply spectacular. Vegetation is much less abundant but the trail is drier and easier to hike. During this season, nights are significantly colder and dressing in multiple layers is essential.