Topography The city of Los Angeles covers a total area of , comprising of land and of water. The city extends for from north to south and for from east to west. The perimeter of the city is . Los Angeles is both flat and hilly. The highest point in the city proper is
Mount Lukens at , located in the foothills of the
San Gabriel Mountains at the north extent of the
Crescenta Valley. The eastern end of the
Santa Monica Mountains stretches from
Downtown to the Pacific Ocean and separates the Los Angeles Basin from the San Fernando Valley. Other hilly parts of Los Angeles include the
Mt. Washington area north of Downtown, eastern parts such as
Boyle Heights, the
Crenshaw district around the
Baldwin Hills, and the
San Pedro district. Surrounding the city are much higher mountains. Immediately to the north lie the
San Gabriel Mountains, which is a popular recreation area for Angelenos. Its high point is
Mount San Antonio, locally known as Mount Baldy, which reaches . Further afield, the highest point in southern California is
San Gorgonio Mountain, east of downtown Los Angeles, with a height of . The
Los Angeles River, which is largely seasonal, is the primary
drainage channel. It was straightened and lined in of concrete by the
Army Corps of Engineers to act as a flood control channel. The river begins in the
Canoga Park district of the city, flows east from the San Fernando Valley along the north edge of the Santa Monica Mountains, and turns south through the city center, flowing to its mouth in the Port of
Long Beach at the Pacific Ocean. The smaller
Ballona Creek flows into the
Santa Monica Bay at
Playa del Rey.
Vegetation in
Playa del Rey Los Angeles is rich in native plant species partly because of its diversity of habitats, including beaches,
wetlands, and mountains. The most prevalent plant communities are
coastal sage scrub,
chaparral shrubland, and
riparian woodland. Native plants include: the
California poppy,
matilija poppy,
toyon,
Ceanothus,
Chamise,
Coast Live Oak,
sycamore,
willow and
Giant Wildrye. Many of these native species, such as the
Los Angeles sunflower, have become so rare as to be considered endangered.
Mexican Fan Palms,
Canary Island Palms,
Queen Palms,
Date Palms, and
California Fan Palms are common in the Los Angeles area, although only the last is native to California, though still not native to the City of Los Angeles. Los Angeles has several official flora: • the official tree of Los Angeles is the Coral Tree (
Erythrina afra) • the official flower is the Bird of Paradise (
Strelitzia reginae) • the official plant is toyon (
Heteromeles arbutifolia)
Fauna The city has an urban
population of
bobcats (
Lynx rufus).
Mange is a common problem in this population.
Mountain lions,
mule deer, and other wild animals are also commonly spotted in Southern California.
Geology , in the
San Gabriel Mountains, is the highest point in LA. Los Angeles is subject to earthquakes because of its location on the
Pacific Ring of Fire. The geologic instability has produced numerous
faults, which cause approximately 10,000 earthquakes annually in Southern California, though most of them are too small to be felt. The
strike-slip San Andreas Fault system, which sits at the boundary between the
Pacific Plate and the
North American Plate, passes through the Los Angeles metropolitan area. The segment of the fault passing through Southern California experiences a major earthquake roughly every 110 to 140 years, and
seismologists have warned about the next "big one", as the last major earthquake was the
1857 Fort Tejon earthquake. The Los Angeles basin and metropolitan area are also at risk from
blind thrust earthquakes. Major earthquakes that have hit the Los Angeles area include the
1933 Long Beach,
1971 San Fernando,
1987 Whittier Narrows, and the
1994 Northridge events. All but a few are of low intensity and are not felt. The USGS has released the
UCERF California earthquake forecast, which models earthquake occurrence in California. Parts of the city are also vulnerable to
tsunamis; harbor areas were damaged by waves from
Aleutian Islands earthquake in 1946,
Valdivia earthquake in 1960,
Alaska earthquake in 1964,
Chile earthquake in 2010 and
Japan earthquake in 2011.
Cityscape The city is divided into many different districts and neighborhoods, some of which had been separately incorporated cities that eventually merged with Los Angeles. These neighborhoods were developed piecemeal, and are well-defined enough that the city has signage which marks nearly all of them.
Overview skyline from
Griffith Park The city's street patterns generally follow a
grid plan, with uniform block lengths and occasional roads that cut across blocks. However, this is complicated by rugged terrain, which has necessitated having different grids for each of the valleys that Los Angeles covers. Major streets are designed to
move large volumes of traffic through many parts of the city, many of which are extremely long;
Sepulveda Boulevard is long, while
Foothill Boulevard is over long, reaching as far east as San Bernardino. Drivers in Los Angeles suffer from one of the worst rush hour periods in the world, according to an annual traffic index by navigation system maker,
TomTom. LA drivers spend an additional 92 hours in traffic each year. During the peak rush hour, there is 80% congestion, according to the index. Los Angeles is often characterized by the presence of
low-rise buildings, in contrast to New York City. Outside of a few centers such as
downtown,
Warner Center,
Century City,
Koreatown,
Miracle Mile,
Hollywood, and
Westwood, skyscrapers and high-rise buildings are not common in Los Angeles. However, downtown Los Angeles alone has many buildings over 30 stories, with fourteen over 50 stories, and two over 70 stories, the tallest of which is the
Wilshire Grand Center.
Climate {{climate chart Los Angeles has a two-season
semi-arid climate (
Köppen:
BSh) with dry summers and very mild winters, but it receives more annual precipitation than most semi-arid climates, narrowly missing the boundary of a Mediterranean climate (
Köppen:
Csb on the coast,
Csa otherwise). Daytime temperatures are generally temperate all year round. In winter, they average around . Autumn months tend to be hot, with major heat waves a common occurrence in September and October, while the spring months tend to be cooler and experience more precipitation. Los Angeles has plenty of sunshine throughout the year, with an average of only 35 days with measurable precipitation annually. Temperatures in the coastal basin exceed on a dozen or so days in the year, from one day a month in April, May, June and November to three days a month in July, August, October and to five days in September. The average annual temperature of the sea is , from in January to in August. Hours of sunshine total more than 3,000 per year, from an average of 7 hours of sunshine per day in December to an average of 12 in July. Due to the mountainous terrain of the surrounding region, the Los Angeles area contains a large number of distinct
microclimates, causing extreme variations in temperature in close physical proximity to each other. For example, the average July maximum temperature at the
Santa Monica Pier is whereas it is in Canoga Park, away. The city, like much of the Southern Californian coast, is subject to a late spring/early summer weather phenomenon called "
June Gloom". This involves overcast or foggy skies in the morning that yield to sun by early afternoon. in the
Santa Monica Mountains More recently, statewide
droughts in California have further strained the city's
water security. Downtown Los Angeles averages of precipitation annually, mainly occurring between November and March, While the most recent snowfall occurred in February 2019, the first snowfall since 1962, with snow falling in areas adjacent to Los Angeles as recently as January 2021. Brief, localized instances of hail can occur on rare occasions, but are more common than snowfall. At the official downtown station, the highest recorded temperature is on September 27, 2010, while the lowest is , During autumn and winter,
Santa Ana winds sometimes bring much warmer and drier conditions to Los Angeles, and raise wildfire risk.
Environmental issues Owing to geography, heavy reliance on automobiles, and the Los Angeles/Long Beach port complex, Los Angeles suffers from air pollution in the form of smog. The
Los Angeles Basin and the
San Fernando Valley are susceptible to
atmospheric inversion, which holds in the exhaust from road vehicles, airplanes, locomotives, shipping, manufacturing, and other sources. The smog season lasts from approximately May to October. While other large cities rely on rain to clear smog, Los Angeles gets only of rain each year: pollution accumulates over many consecutive days. Issues of air quality in Los Angeles and other major cities led to the passage of early national environmental legislation, including the
Clean Air Act. When the act was passed, California was unable to create a
State Implementation Plan that would enable it to meet the new air quality standards, largely because of the level of pollution in Los Angeles generated by older vehicles. More recently, the state of California has led the nation in working to limit pollution by mandating
low-emission vehicles. Smog is expected to continue to drop in the coming years because of aggressive steps to reduce it, which include
electric and
hybrid cars, improvements in
mass transit, and other measures. The number of Stage 1 smog alerts in Los Angeles has declined from over 100 per year in the 1970s to almost zero in the new millennium. Despite improvement, the 2006 and 2007 annual reports of the
American Lung Association ranked the city as the most polluted in the country with short-term particle pollution and year-round particle pollution. In 2008, the city was ranked the second most polluted and again had the highest year-round particulate pollution. The city met its goal of providing 20 percent of the city's power from renewable sources in 2010. The American Lung Association's 2013 survey ranks the metro area as having the nation's worst smog, and fourth in both short-term and year-round pollution amounts. Los Angeles is also home to the nation's largest urban
oil field. There are more than 700 active oil wells within of homes, churches, schools, and hospitals in the city, a situation about which the
EPA has voiced serious concerns. ==Demographics==