Central Asia experiences wild extremes of temperature. While high summer (June to August) in the desert regions tends to be blisteringly hot, in winter the thermometer may not rise above freezing for weeks on end. For exploring the monuments, spring and autumn are preferable, with dependably blue skies, warm sunshine and pleasant evenings the norm. From late October, temperatures in the mountains start to plummet, and heavy snow closes some high passes from November until April.