Xiamen has a monsoonal humid subtropical climate , characterised by long, hot and humid summers (but moderate compared to much of the rest of the province) and short, mild and dry winters. The warmest month is July, with a 24-hour average of 27.8 °C (82.0 °F), and the coolest month is January, averaging 12.8 °C (55.0 °F); the annual mean is 20.7 °C (69.3 °F). Extremes since 1951 have ranged from 1.5 °C (35 °F) on 29 December 1991 to 39.2 °C (103 °F) on 20 July 2007. Spring, both by humidity and percentage of sunshine, is the dampest season but typhoons in late summer and early autumn can make the latter period wetter overall. Summer and autumn are marked by comparatively sunny conditions, while autumn is warm and dry. The annual rainfall is 1,350 millimeters (53 in). With monthly percent possible sunshine ranging from 24% in March to 56% in July, the city receives 1,853 hours of bright sunshine annually. Frost occurs very rarely, and the last snowfall in the city took place in January 1893, when snow also fell at Guangzhou, Macau, in the inland parts of Hong Kong and in the hills of Taipei.
The area is known within China for its relatively low pollution.