Turpan has one of the most extreme climates in China — the Turpan Depression, at 154 metres below sea level, is the second-lowest land point in Asia and one of the hottest. Summer (June through August) regularly exceeds 45°C, with overnight lows still in the 30s. Even with shade and the legendary local grapes and watermelons, midday outside is brutal.
The most comfortable windows are April–May and late September–October, when daytime temperatures are 20–30°C and the desert basin is at its most photogenic. Late September coincides with the grape harvest and the annual Turpan Grape Festival.
Winter (December–February) is cold and quiet, with daytime highs near or below freezing. Many smaller sites close or run reduced hours. Spring sandstorms occasionally blow in from late March into May; check the forecast.