Iran has a highly diverse climate, but most of the country is arid to semi-arid, with low rainfall and hot, sunny summers. Cooler, wetter conditions occur along the Caspian coast and in the western mountain belts, while the interior plateau and southeastern lowlands are much drier and more extreme. Recent references describe the national climate as mainly continental and dry, with strong regional contrasts in temperature and precipitation. For residents and expats, comfort depends heavily on location: coastal and highland cities are more moderate, while inland and desert areas can be intensely hot in summer and cold in winter.