Within the Inland Empire metropolitan area, Riverside is both a city and the county seat of Riverside County, California, in the United States. Because of is proximity to the Santa Ana River, it has such name. Situated approximately 50 miles southeast of downtown Los Angeles, it is the most populated city in Riverside County and the Inland Empire. It is a component of the Greater Los Angeles region as well. Riverside is the largest city in California's Inland Empire metro area, the 61st largest city in the US, and the 12th largest city in the state. The city has an area of 81.4 square miles, of which 81.1 square miles are land and 0.3 square miles (0.37%) are water, according to the US Census Bureau.

The climate of Riverside, California, is semi-arid to arid, with hot, dry summers and warm, comparatively moist winters. December's typical monthly temperature is 54.8 °F, while August's mean temperature is 79.8 °F. Riverside has 100°F heat and freezing cold on 3.5 and 21.6 days per year, respectively. With an average of 9.39 inches per year, precipitation primarily falls between November and April. From 18 °F on January 15, 1911, to 118 °F on July 17, 1925, are the recorded temperatures. Located in the heart of the Inland Empire, Riverside has a variety of climates due to its proximity to both large and small mountains, as well as the rare winter snowfall.

In addition to hosting year-round activities, Riverside is home to a number of museums, including the March Field Air Museum and Riverside Art Museum. The Riverside Airshow in March attracts 70,000 visitors with its aerial displays and aircraft exhibits, while the Riverside Dickens Festival in February honors literature and community. A significant air show that includes both military and civilian demonstrations is the biennial March Field Airfest. April's Riverside International Film Festival features international film, and May has the Old Riverside Foundation's Vintage Home Tour. The Riverside Festival of Lights and the Ghost Walk are decked with spectacular lights in October, and Thanksgiving week is the time for the Festival of Trees, which auctions off decorated trees to raise money for local medical clinics.

Riverside is home to a wide range of academic institutions. The University of California, Riverside, National University, California Baptist University, La Sierra University, and Riverside City College are among the institutions of higher learning. The educational landscape of the city is influenced by secondary schools like Arlington High School and La Sierra High School as well as vocational schools like Brightwood College. Among the notable establishments in Riverside are schools for certain student populations, like Sherman Indian High School for Native American tribal members and the California School for the Deaf, Riverside, which serves the Deaf and Hard of Hearing. Riverside's educational offerings are enhanced by the presence of private secondary schools such as Bethel Christian School and Notre Dame High School.

Riverside benefits from an efficient transit system. In northeastern Riverside, a contemporary multi-level junction greets the convergence of three major freeways: I-215, State Route 60, and State Route 91. Three Metrolink commuter train stations provide easy access to the city via rail connections: Riverside-Downtown, Riverside-La Sierra, and Riverside-Hunter Park/UCR. Riverside is also a stop on Amtrak's Southwest Chief, which runs from Los Angeles to Chicago. Effective public transportation is made possible by local and intercity bus services, which are run by the Riverside Transit Agency and operators like Omnitrans Greyhound Lines and Amtrak California. The closest commercial airport is Ontario International Airport, however the Riverside Municipal Airport mostly handles private aircraft and is home to the annual Riverside Air Show.