Echmiadzin sits on the open Ararat plain, which makes for very hot summers and cold winters. April to June and September to October are the easiest months: clear skies, comfortable temperatures, and Mount Ararat usually visible from Zvartnots.
Religious holidays are the most atmospheric (and busiest) times. Easter is the great festival of the Armenian Apostolic Church, with all-night services in the cathedral. The Feast of Vardavar in July — a Christianised pagan festival — is celebrated with water-throwing in the streets; pilgrims of all ages get drenched. Major ordinations and the consecration of the holy myron (chrism), every seven years, draw enormous crowds.