Dalian is a major city and seaport in the south of Liaoning Province, People's Republic of China. It is the southernmost city of Northeast China and at the tip of the Liaodong Peninsula. Dalian is the province's second largest city and has sub-provincial administrative status; only the provincial capital (Shenyang) is larger. The Shandong Peninsula lies southwest across the Bohai Strait; Korea lies across the Yellow Sea to the east.
Dalian was previously known as both Dalniy (Russian: Дальний; Dal'nii) and Dairen (Japanese: 大連). However the city was better known as Port Arthur (Russian: Порт-Артур; Port-Artur) and Ryojun (Japanese: 旅順) from the original Port Arthur, now the Lüshunkou district.
One of the most heavily developed industrial areas of China, Dalian municipal area today consists of Dalian proper and the smaller Lüshunkou (formerly Lüshun city, known in Western and Russian historic references as Port Arthur), about 40 nautical miles (74 kilometers; 46 miles) farther along the Liaodong Peninsula. Historical references note that the Russian designed city of Dalniy (Alt. Dalney), on the south side of Dalian Bay was 25 miles (40.23 kilometers) from Port Arthur/Lüshun (known today as Lüshunkou or literally, Lüshun Port).
Dalian is located on Korea Bay north of the Yellow Sea and roughly in the middle of the Liaodong peninsula at its narrowest neck or isthmus. With a coastline of 1,184 miles (1,905.5 kilometers), it governs the majority of the Liaodong Peninsula and about 260 surrounding islands and reefs. It is seated at south-south-west of the Yalu River, and its harbor entrance forms a sub-bay known as Dalian Bay.
Dalian has a monsoon-influenced humid continental climate (Köppen Dwa), characterized by humid summers due to the East Asian monsoon, and cold, windy, dry winters that reflect the influence of the vast Siberian anticyclone. Except for winter, the city experiences a one-month seasonal lag due to its position on the Liaodong Peninsula. The monthly 24-hour average temperature ranges from −3.9 °C (25.0 °F) in January to 24.1 °C (75.4 °F) in August. Annual precipitation averages 602 millimeters (23.7 in) but is heavily concentrated in the summer months and can vary greatly from year to year. Due to the coastal location, the mean diurnal temperature variation annually is small, at 6.75 °C (12.2 °F). The monthly percent of possible sunshine ranges from 49% in July to 68% in September and October, with 2,740 hours of bright sunshine annually. The annual mean temperature is 10.90 °C (51.6 °F). Extremes since 1951 have ranged from −21.1 °C (−6 °F) on January 4th, 1970 to 36.6 °C (98 °F) on July 14th, 2015.