Don't expect a rainforest here, but the climate of Yemen does have its moist side. Every summer, a powerful low-level jet stream arcs from Somalia toward India. As the strong flow approaches Yemen's soaring western highlands, it can trigger substantial rains and thunderstorms. The high terrain picks up other moisture through the rest of the year – snow even falls at the highest peaks – with the most favoured locales experiencing as much as 500mm/20in of precipitation. Summer showers may fall along the Gulf of Aden coast, but the rest of the nation, especially the interior desert, is more conventionally arid. Conditions are hot year-round at lower elevations, with perpetual humidity on the coasts. Altitude allows the high plateau, surrounded by mountains topping 3500m/11,500ft, to stay amazingly mild.