It is located on the western coast of Hainan Island facing Vietnam across the Gulf of Tonkin, and in 2004 had a population of 435,000.

Rainfall is heaviest and most frequent from August to October, when typhoons may strike, and averages an annual total of 1,042.1 mm (41.0 in), far lower than much of the island.

January through March features the highest relative humidity levels of the year, while May through August is very sunny, consistently averaging above 60% of possible sunshine.

3Prefecture capital status established by Heilongjiang Province and not recognized by Ministry of Civil Affairs.

5The claimed province of Taiwan no longer have any internal division announced by Ministry of Civil Affairs of PRC, due to lack of actual jurisdiction.