Tsaghkadzor has two distinct seasons worth visiting for. Winter — roughly December to March — brings reliable snow above 2,000m and is when the ski resort operates at full capacity. Weekends fill up with Yerevan day-trippers; if you want the slopes quieter, come on a weekday. February is usually the best month for snow depth and cold clear days.
Summer (June to September) is warm and dry at altitude, with temperatures in the low-to-mid 20s. The gondola runs throughout the summer season, and the surrounding Tsakhkunyats mountain range is excellent walking country. Wildflowers are particularly good in June and early July. Spring and autumn are shoulder seasons — fewer crowds, lower prices, but the ski lifts are closed and the weather can be unsettled.