The climate is tropical monsoonal characterized by a short rainy season, prolonged dry season, and irregular occurrence of rainfall both from year to year and within years. Most rain falls between May and mid-November. Total average annual rainfall varies greatly from province to province. While the annual rainfall in Phnom Penh and Battambang is 1375 mm and 1387 mm, respectively, Kampong Speu receives only 1204 mm, and Kampong Som has 383l mm. May. The population is estimated to be about 9 million.
Primary produce is a major contributor to Cambodia's foreign trade.
Agricultural exports include rubber, timber, fish, maize, soybean, sesame, and tobacco. Importance of rice Rice is by far the most important staple food of Cambodia. About 2.5 million ha were planted to rice in the 1960s. Currently, Cambodia cultivates approximately 1.8 million ha. There is considerable potential for increasing production through an expanded area.