The climate of Bhutan varies greatly depending on the altitude and region you are in. The high season for travel in Bhutan is between March and May and September and November. In the south temperatures range from 15 degrees in winter to 30 degrees in summer, where as in the north the temperatures are more extreme ranging from -5 degrees in winter to 30 degrees in summer time. Summer time is June to August and winter time is December to February. In the mountains the average temperature is 0 degrees in winter and 10 degrees in summer time. Bhutan also receives the highest rainfall of any of the Himalayan countries. The monsoon travels from south to west in June through to September and can dump an average of 5.5m of rain in certain regions.