The American state of California's Orange County contains the city of Costa Mesa. The distances of Costa Mesa from Los Angeles, San Diego, and San Francisco are 37 miles southeast, 87 miles northwest, and 425 miles southeast respectively. With its southern boundary just one mile from the Pacific Ocean, Costa Mesa spans an area of sixteen square miles.

Warm temperatures all year round are a feature of Costa Mesa's semi-arid climate (Köppen climatic classification BSh). Winter brings most of the precipitation to the city, with very little falling in the summer months. From 1991 to 2020, climate data for John Wayne Airport in California shows stable trends in temperature. With a record high of 110°F (43°C) in September, the month usually experiences the greatest temperatures in the area. In December, the average daily maximum temperature is 66.5°F (19.2°C), while in July, it is 78.9°F (26.1°C). The average annual precipitation is 11.18 inches (284 mm) with an average of 41.3 precipitation days. Overall, the region is characterized by moderately warm temperatures and little precipitation.

Higher education facilities including Vanguard University and Orange Coast College are located in Costa Mesa. Whittier Law School used to be a part of the academic scene. Tewinkle Middle School, Costa Mesa Middle School, Costa Mesa High School, and Estancia High School are the public high schools that serve the city. While Coastline Early College High School has its own facilities, alternative high schools Back Bay High School and Monte Vista High School share a site. The Newport-Mesa Unified School District is home to several educational institutions.

The main drivers of Costa Mesa's economy are services and retail, particularly South Coast Plaza, a well-known mall that brings in more than $1 billion a year. Electronics and pharmaceutical manufacturing are located in the city's industrial southwest section. The biggest employer in Costa Mesa is a multinational business services corporation called Experian. The city's economy is bolstered by notable companies including Toyota Racing Development, El Pollo Loco, and Ceradyne. Costa Mesa is where Wahoo's Fish Taco first opened its doors in 1988. Public schools, parks, and a municipal golf course are among the facilities offered by the city. The city's workforce is significantly shaped by major employers, such as Winfield Locks, Inc., El Pollo Loco, and Experian, as the 2020 Comprehensive Annual Financial Report details.