Temperatures in the dry season, from May to November, average 20°–33° C (68–91° F ). The weather during this season is pleasant and dry. Around October or November, oppressive humidity arrives, and monsoon cloud activity builds up. The wet season, from December to April, sees average temperatures of 29°–35° C (84–95° F ), with heavy rains and flooding. In the mountains, day temperatures are warm to hot, but are cool to cold at night. Earthquakes, tsunamis, and tropical cyclones occur.