The high mountainous areas of Europe are colder and have higher precipitation than lower areas, as is true of mountainous areas in general. Europe has less precipitation in the east than in central and western Europe. The temperature difference between summer and winter gradually increases from coastal northwest Europe to southeast inland Europe, ranging from Ireland, with a temperature difference of only 10 °C from the warmest to the coldest month, to the area north of the Caspian Sea, with a temperature difference of 40 °C. January average range from 13 °C in southern Spain and southern Greek islands to -20 °C in the northeastern part of European Russia. Desert climates are found in the European portion of Kazakhstan and South Eastern Spain.