Lu'an (Chinese: 六安; pinyin: Lù'ān), is a prefecture-level city in western Anhui province, People's Republic of China, bordering Henan to the northwest and Hubei to the southwest. At the 2010 census, it had a total population of 5,612,590, whom 1,644,344 resided in the built-up area made of 2 urban districts. Neighbouring prefecture-level cities are the provincial capital of Hefei to the east, Anqing to the south, Huanggang (Hubei) and Xinyang (Henan) to the west, and Huainan and Fuyang to the north. Although the character "六" (literally: "six") is normally pronounced "Liù", in this case it changes to "Lù" on account of the historical literary reading.
Lu'an is marked by the southern fringes of the North China Plain in its north and the northern part of the Dabie Mountains in its south. Its administrative area spans 31°01′−32°40′ N latitude and 115°20′−117°14′ E longitude.
Lu'an has a monsoon-influenced, humid subtropical climate (Köppen Cfa), with four distinct seasons. Winters are cold and damp, with average low temperatures in January dipping just below freezing; the January 24-hour average temperature is 2.6 °C (36.7 °F). Summers are typically hot and humid, with a July average of 27.8 °C (82.0 °F). The annual mean is 15.68 °C (60.2 °F), while annual precipitation averages just above 1,100 millimetres (43 in), a majority of which occurs from May to August. Annual sunshine duration is 2,000 to 2,300 hours.