Description & Facts: Los Angeles is irregularly shaped and covers a total area of 498.3 square miles (1,291 km2), comprising 469.1 square miles (1,214.9 km2) of land and 29.2 square miles (75.7 km2) of water. The city extends for 44 miles (71 km) longitudinally and for 29 miles (47 km) latitudinally. The perimeter of the city is 342 miles (550 km). It is the only major city in the United States bisected by a mountain range. Map of Los AngelesThe highest point in Los Angeles is Mount Lukens, also called Sister Elsie Peak. Located at the far reaches of the northeastern San Fernando Valley, it reaches a height of 5,080 ft (1,548 m). The major river is the Los Angeles River, which begins in the Canoga Park district of the city and is largely seasonal. The river is lined in concrete for almost its entire length as it flows through the city into nearby Vernon on its way to the Pacific Ocean. Los Angeles is subject to earthquakes due to its location in the Pacific Ring of Fire. The geologic instability produces numerous fault lines both above and below ground, which altogether cause approximately 10,000 earthquakes every year. One of the major fault lines is the San Andreas Fault. Located at the boundary between the Pacific Plate and the North American Plate, it is predicted to be the source of Southern California's next big earthquake. Major earthquakes to have hit the Los Angeles area include the 2008 Chino Hills earthquake, 1994 Northridge earthquake, the 1987 Whittier Narrows earthquake, the 1971 San Fernando earthquake near Sylmar, and the 1933 Long Beach earthquake. Nevertheless, all but a few quakes are of low intensity and are not felt. The most recent earthquake felt was the 5.4 Chino Hills earthquake on July 29 2008. Parts of the city are also vulnerable to Pacific Ocean tsunamis; harbor areas were damaged by waves from the Valdivia earthquake in 1960. The Los Angeles basin and metropolitan area are also at risk from blind thrust earthquakes. Los Angeles has a Mediterranean climate or Dry-Summer Subtropical (Koppen climate classification Csb on the coast, Csa inland). Los Angeles enjoys plenty of sunshine throughout the year, with an average of 263 sunshine days and only 35 days with measurable precipitation annually. Echo Park as seen with Palm TreesThe period of May through October is warm to hot and dry with average high temperatures of 74 - 84F (24 - 29C) and lows of 58 - 66F (14 - 19C), however temperatures frequently exceed 90F (32C) and occasionally reach 100F (38C) in inland areas (away from the moderating effect of the ocean). The period of November through April is mild and somewhat rainy with average high temperatures of 68 - 73F (20 - 23C) and lows of 48 - 53F (9 - 12C), but temperatures could occasionally drop to low 40s (~5C) or be as high as 80F (26C) for few days during winter. The Los Angeles area is also subject to the phenomenon typical of a microclimate. As such, the temperatures can vary as much as 18F (10C) between inland areas and the coast, with a temperature gradient of over one degree per mile (1.6 km) from the coast inland. California has also a weather phenomenon called "June Gloom or May Grey", which sometimes gives overcast or foggy skies in the morning at the coast, but usually gives sunny skies by noon, during late spring and early summer. Los Angeles averages 15 inches (385 mm) of precipitation annually, which mainly occurs during the winter and spring (November thru April) with generally light rain showers, but sometimes as heavy rainfall and thunderstorms. The coast gets slightly less rainfall, while the mountains get slightly more. Years of average rainfall are rare; the usual pattern is bimodal, with a short string of dry years (perhaps 7-8 inches/175-200 mm) followed by one or two wet years that make up the average. Snowfall is extremely rare in the city basin, but the mountains within city limits slopes typically receive snowfall every winter. The greatest snowfall recorded in downtown Los Angeles was 2 inches (5 cm) in 1932.