Because Vietnam extends so far from north to south, the weather varies substantially throughout the country. While its climate is mostly tropical overall, the north of the country experiences more seasonal variation and gets surprisingly chilly in the winter. Summer and early fall is the rainiest time of year in the north. In central Vietnam, the temperatures are generally warmer, and the rainy season is in the fall. Southern Vietnam is hot and humid year-round, with the heaviest rains in the summer and early fall.