April to early June and September to October are the best months in Samarkand. Days are warm and clear, evenings are cool, the spring is green and the autumn light is golden on the tilework. The Silk and Spices Festival in late August fills the Registan with stalls and music.
July and August are punishingly hot — daytime temperatures push above 40°C with little shade. November to March is cold, with snow possible from December to February; the monuments are quiet but the upper galleries of the Registan and Shah-i-Zinda can be slippery and bitter, and many of the rooftop cafes close.
Hotels fill quickly in May, September, and during national holidays — Navruz on 21 March is the big one. Book ahead.