Nanjing has a humid subtropical climate (Köppen Cfa) and is under the influence of the East Asian monsoon. The four seasons are distinct, with damp conditions seen throughout the year, very hot and muggy summers, cold, damp winters, and in between, spring and autumn are of reasonable length. Along with Chongqing and Wuhan, Nanjing is traditionally referred to as one of the "Three Furnacelike Cities" along the Yangtze River (长江流域三大火炉) for the perennially high temperatures in the summertime. However, the time from mid-June to the end of July is the plum blossom blooming season in which the meiyu (rainy season of East Asia; literally "plum rain") occurs, during which the city experiences a period of mild rain as well as dampness. Typhoons are uncommon but possible in the late stages of summer and early part of autumn. The annual mean temperature is around 15.46 °C (59.8 °F), with the monthly 24-hour average temperature ranging from 2.4 °C (36.3 °F) in January to 27.8 °C (82.0 °F) in July. Extremes since 1951 have ranged from −14.0 °C (7 °F) on 6 January 1955 to 40.7 °C (105 °F) on 22 August 1959. On average precipitation falls 115 days out of the year, and the average annual rainfall is 1,062 millimetres (42 in). With monthly percent possible sunshine ranging from 37 percent in March to 52 percent in August, the city receives 1,983 hours of bright sunshine annually.