Autumn in Humahuaca brings mild days of 20°C (68°F) and crisp nights near 5°C (41°F), perfect for exploring the Quebrada. As rains fade, the Valley of Colors glows under clear skies, highlighting Hornocal's striped peaks. Hike to Pucará de Tilcara's ruins or wander Purmamarca's adobe streets during the less crowded September harvest. This UNESCO site offers ideal conditions for trekking, photography, and experiencing local folklore festivals before winter chills set in across the high Andes landscape.