Athens has a hot-summer Mediterranean climate (Köppen climate classification: ''Csa''). The dominant feature of Athens' climate is alternation between prolonged hot and dry summers because of the dry and hot winds blowing from the Sahara, and mild, wetter winters with moderate rainfall, due to the westerly winds. With an average of  of yearly precipitation, rainfall occurs largely between the months of October and April. July and August are the driest months when thunderstorms occur sparsely. Furthermore, some coastal areas of Athens, known as the Athens Riviera have a hot semi-arid climate (''BSh'') according to the climate atlas published by the Hellenic National Meteorological Service. However, places like Elliniko, which are classified as hot semi-arid (''BSh'') because of the low annual rainfall, have not recorded temperatures as high as other places in the city. This happens because of the moderating sea and the fact that there is not as much industrialization as in other regions of the city.