The 2011 median household income of $77,006 was the fifth-highest in New York (after Nassau, Putnam, Suffolk, and Rockland counties) and the 47th highest in the United States.

Westchester County high school students often feature prominently as winners of the International Science and Engineering Fair and similar STEM-based academic awards.

The period following the American Civil War enabled entrepreneurs in the New York area to create fortunes, and many built large estates, such as Lyndhurst, in Westchester.

During the latter half of the 19th century, Westchester's transportation system and labor force attracted a manufacturing base, particularly along the Hudson River and Nepperhan Creek.

Westchester's Long Island Sound shore is generally rocky, interspersed with tidal mud flats, marshes and wetlands, as well as several natural and artificially-maintained sand beaches.

Municipal and county owned parks provide access to beaches, nature preserves and passive and active waterfront recreational facilities.

The widest section of the Hudson River, at 3.6 miles (6 km), is found between the Westchester and Rockland County shorelines immediately north of Croton Point.

The Hudson River waterfront in Westchester is in a transitional period, converting from primarily industrial uses to mixed residential, commercial, retail, and recreational uses.

This transformation is most notable in Yonkers, Hastings-on-Hudson, Dobbs Ferry, Irvington, Tarrytown, Sleepy Hollow, Ossining, and Peekskill, where redevelopment projects are in various stages of design and completion.

[16] At 987 feet (301 m), the highest elevation in the county is a U.S. Coast and Geodetic Survey benchmark known as "Bailey" in Mountain Lakes Park near the Connecticut state line.

The system is a series of interconnected reservoirs and lakes in northern Westchester and Putnam Counties that provide 10% of New York City's water under normal conditions and up to 30% in times of drought.

According to the 2020 American Community Survey, the county's Latino population was: 5.12% Puerto Rican, 4.46% Dominican, 4.14% Mexican, 2.73% Ecuadorian, 1.73% Guatemalan, 1.26% Colombian.

For instance, the ZIP Codes for Bronxville, Larchmont, Rye, and Scarsdale contain large areas that lie outside of those municipalities.

[35] In April 2017, county officials unveiled plans for an 80-acre, 3 million square-foot biotechnology hub to be built with US$1.2 billion in private investment on vacant land adjacent to Westchester Medical Center in Valhalla; the bioscience center, a public-private partnership, is anticipated to create 12,000 new jobs and include over 2.25 million square feet of biotechnology research space.

[12] According to the 2018 rankings provided by the education website Niche, taking into account public comments, 28 of the top 100 school districts in the state of New York were located in Westchester County.

Philipse Manor Hall is located in Getty Square, Yonkers, and is operated by the New York State Office of Parks, Recreation and Historic Preservation.

The only exceptions were 1912, when the GOP was divided between William Howard Taft and Theodore Roosevelt, and 1964, when Lyndon B. Johnson won a national landslide and swept every county in New York.

In fact, Westchester, after New York City and Albany County, has produced the biggest margins for statewide Democrats in recent years.

For instance, it voted for Republican George Pataki, by a margin of 23.07% against Democratic candidate, Carl McCall in the gubernatorial race of 2002, and by 26.22% in 1998.

In 2006, county legislator Andrea Stewart-Cousins defeated 20-year incumbent Nicholas Spano for a seat in the New York State Senate in a rematch of the 2004 race, which she had lost by only 18 votes.

In 2009, Republican Rob Astorino ousted three-term county executive Andy Spano, who had the endorsement of the New York Conservative Party, winning in a landslide.

Westchester County was the home of U.S. Vice President Nelson Rockefeller, who occupied the Kykuit mansion near the hamlet of Pocantico Hills.

Over 700 firefighters, police officers and EMS providers were trained to be part of this effort and serve over half the population of Westchester County including Yonkers, Mount Vernon, New Rochelle, White Plains, Scarsdale, Eastchester, and the Fairview, Hartsdale, and Greenville Fire Departments in the Town of Greenburgh.

Additionally, NY Waterway operates a water ferry service between Ossining in Westchester and Haverstraw in Rockland County.

The story has inspired a variety of works, including the 2013 television series Sleepy Hollow, set in the modern village.

In print media, the area is a frequent setting of the Nero Wolfe detective stories by Rex Stout, which ran from 1934 to 1975.

The original author, Julie Campbell Tatham, modeled the fictional Crabapple Farm in Sleepyside after her own home at Wolf Hollow on Glendale Road in Ossining.

Westchester is the primary setting and residence of the main characters in The Clique young adult novel series by Lisi Harrison.

In television, an early broadcast media presentation of Westchester County was on The Dick Van Dyke Show (1961–1966), whose main characters live in New Rochelle.

[57] In the final season of the American sitcom Friends, the characters Monica and Chandler moved from New York City to live in Westchester.