Chichén Itzá Autumn Equinox — Descent of Kukulkán 2026

At El Castillo pyramid, the afternoon sun creates a serpent-shadow effect on the northern staircase — the "Descent of Kukulkán". Best viewed 15:00–17:30. Annual equinox phenomenon.

Twice a year, at the spring and autumn equinoxes, the setting sun casts a cascading pattern of triangular shadows along the northern balustrade of El Castillo (Temple of Kukulkán) at Chichén Itzá, creating the illusion of a feathered serpent descending the pyramid. The autumn 2026 equinox falls on 22 September. The effect is most pronounced between 15:00 and 17:30. Afternoon showers are possible in September. Sources: chichenitza.com/equinox; INAH (Instituto Nacional de Antropología e Historia).