Although influenced by a continental climate, traces of an oceanic climate can be detected in Incheon thanks to its location on the coast. This is why the city is subject to a smaller annual temperature range. The average temperature for the year in Incheon is 12.1℃ while the highest temperature recorded was 38.9℃ (August 16, 1949) and the lowest recorded was -21.0℃ (January 11, 1931). Precipitation is at 1,234.4mm per year which is a low amount compared to other regions at similar latitudes. The average wind speed throughout the year is 2.9m/s which blows primarily north-northwest followed by north and northwest. February ~ April endures the strongest winds while September experiences the mildest. Compared to other regions, Incheon suffers from yellow dust more frequently and the dust tends to persist for longer periods of time as well. When migratory anticyclones from central China increase the amount of southwesterly winds, it creates heavy fog on the Yellow Sea and prevents temperatures rising during the day. The total number of foggy days in Incheon is 49.4 days of which 64% occur between April and July.
When Incheon was elevated into a Directly Governed City on July 1, 1981, it was 201.21km². When Gyeyang-myeon in Gimpo-gun (30.9km²), Yeongjong and Yongyu-myeon (72.0km²) from Gyeonggi Province were integrated into Incheon on January 1, 1989, the city grew to 310.83km². Later on, when the city was renamed as a Metropolitan City on January 1, 1995, Ganghwa-gun (401.3km²), Ongjin-gun (163.6km²), and Geomdan-myeon in Gimpo-gun (42.2km²) were once again integrated into Incheon. On November 10, 2016, Incheon became the largest of Korea's eight metropolitan cities in terms of land area. With the completion of the land registration process for land created through coastal land reclamation projects, the city has extended in size by 7.7 square kilometers since 2015. The total area of Incheon Metropolitan City is now 1,062.1 square kilometers, making it larger than Ulsan Metropolitan City, which was once the largest city in Republic of Korea (1,061 square kilometers). After Incheon and Ulsan, the largest cities in Republic of Korea in terms of land area are Daegu (883.6 square kilometers), Busan (769.8 square kilometers), and Seoul (605.3 square kilometers).
As of January 31, 2015, Incheon Metropolitan City's has 8 gu districts, 2 gun districts, 1 eup district, and 128 dong districts. As at December 31, 2016, the city's registrated population stood at 3,002,172, making it the third most populous city in Republic of Korea, after Seoul and Busan. Currently, there are 59,103 foreigners living in Incheon (as of December 2016)
Apart from roughly 10 mountains including Manisan Mountain (469m), Gyeyangsan Mountain (395m), and Samgaksan Mountain (343m), the mountain ranges in Incheon have gentle gradients and are lower than 300m above sea level in height. As a result, the city has no major river. Incheon has estuaries such as Gulpocheon, Cheongcheoncheon, and Gyesancheon that flow into Hangang River, along with estuaries such as Sicheoncheon and Gongcheoncheon to the north and Seunggicheon, Mansucheon, Jangsucheon, and Unyeoncheon to the south that flow into the Yellow Sea. Except for Gulpocheon (11.5km), most rivers including Seunggicheon (6.2km) and Geomdancheon (6.74km) are less than 10km in length. Incheon is also home to a ria coast which means it has a long and complex coastline with plenty of islands. There are a total of 168 islands in Incheon of which 128 are uninhabited.
The expansion of Incheon Harbor and opening of Incheon Subway (October 1999), opening of the Incheon International Airport (March 2001), landfill of public waters, construction of various industrial and logistics complexes, construction of tourism and leisure complexes and new residential areas, upgrade of highways, expansion of education and cultural facilities, development of Songdo New Town and opening of the Free Economic Zone (October 2003), construction of Incheon Bridge (October 2009), development of Cheongna and Yeongjong districts and urban restoration projects, and the successful execution of the 2014 Asian Games shows that Incheon continues to develop and grow at this very moment. Also Incheon hosted the Presidents Cup, a prestigiousevent that is renowned amongst golfers internationally, in October 2015. This was a great opportunity to introduce Incheon to 225 countries in 30 languages to more than a billion people around the world.