Region Los Angeles


The Los Angeles region, which includes Los Angeles, Orange, Ventura, and the western portions of San Bernardino and Riverside counties, is home to many different ecosystems ranging from coasts, mountains, and desert interior landscapes. The region’s Mediterranean climate is characterized by hot, dry summers and cool, wet winters, which allow for agricultural production. Snow-based water from the Sierra Nevada and Colorado Rockies has historically satisfied the region’s large residential, industrial, agricultural, and ecological freshwater demands. The region’s primary economic drivers include entertainment and digital media industries, international trade, defense contracting, medicine, and a growing high-tech sector. Home to more than 18 million people, this region contains approximately half of California’s population.


Average maximum temperatures in the Los Angeles region are expected to increase 4-5°F by mid-century and 5-8°F by late century. Alongside this average maximum temperature increase, extreme temperatures and extreme hot days are also expected to increase. The hottest day of the year may be up to 10°F warmer for many locations across the Los Angeles region by mid-century.


Oscillation between dry and wet extremes are projected to increase. Increased frequency and severity of rain events are also projected to occur for this region, alongside a potential doubling in frequency of extremely dry years by late century. Dry extremes will contribute to increased wildfire occurrence and severity. Current projections indicate that burned area will increase 60-75 percent.


Sea-levels will continue to rise in the future. By mid-century, sea-level rise is expected to increase by 1.1 – 1.9 feet. By end of century, projections indicate 3.3 – 6.8 feet of sea-level rise, with the potential for 10 feet under extreme sea-level rise scenarios. Rising seas, in combination with large wave events, will lead to more coastal flooding onshore.

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