In 2015, Somerset County had aper capita personal income of $86,468, the second highest in New Jersey and ranked 25th of 3,113 counties in the United States.[11][12] Somerset County, as of the 2000 Census, was theseventh wealthiest county in the United States bymedian household income at $76,933 (third in New Jersey behindHunterdon County at $79,888 andMorris County at $77,340), fourth in median family income at $90,655 (second in New Jersey behind Hunterdon County at $91,050) and ranked seventh by per capita income at $37,970 (highest in New Jersey).[13] TheBureau of Economic Analysis ranked the county as having the 11th-highestper capita income of all 3,113 counties in the United States (and the highest in New Jersey) as of 2009.[14] As of 2023, Somerset County had the highest GDP for counties with populations between 100,000 and 500,000 in America.[15]
In 2012, 49.8% of Somerset County residents were college graduates, the highest percentage in the state.[16] Somerset County was recently ranked number three of 21 NJ counties as one of the healthiest counties in New Jersey, according to an annual report by County Health Rankings and Roadmaps.[17] Somerset County was created on May 14, 1688, from portions ofMiddlesex County.[1]
The area was first settled in 1681 in the vicinity ofBound Brook,[citation needed] and the county was established by charter on May 22, 1688. Most of the early residents wereDutch.[citation needed]
During theAmerican Revolutionary War,GeneralGeorge Washington and his troops marched through the county on several occasions and slept in many of the homes located throughout the area. Somerset County also played an important part during bothWorld War I andWorld War II. Weapons depots were established here, and factories manufactured the army's woolen blankets. For much of its history, Somerset County was primarily an agricultural county. In the late 19th century, theSomerset Hills area of Somerset County became a popular area for country homes built by wealthy industrialists. The area continues to be the home of wealthy people who own businesses.[18]
In 1917, Somerset County, in cooperation withRutgers University, hired its first agricultural agent to connect local farmers with expert advice. The Rutgers Cooperative Extension of Somerset County, located in Bridgewater, serves residents in the areas of agriculture and natural resources,4-H youth development, and family and community health sciences.[19] In the 1960s, townships which were once exclusively agricultural were quickly developed as suburban residential communities. Examples includeBridgewater Township[20] and the Watchung Hills communities ofWatchung,Green Brook Township andWarren Township.[21][22][23] The growth was aided by the development of the county's very strong pharmaceutical and technology presence.Warren Township used to be considered "the greenest place in New Jersey."[21] More recently, an influx has occurred of New York City commuters who useNJ Transit'sRaritan Valley Line andGladstone Branch or useInterstate 78.
According to theU.S. Census Bureau, as of the 2020 Census, the county had a total area of 304.95 square miles (789.8 km2), of which 3.09 sq mi (8.0 km2) were covered by water.[26]
The highest point in the county is on Mine Mountain in Bernardsville, around 860 feet (260 m) above mean sea level.[27] The lowest point is just above sea level on theRaritan River at the Middlesex County line.
In recent years,[when?] average temperatures in the county seat of Somerville have ranged from a low of 18 °F (−8 °C) in January to a high of 85 °F (29 °C) in July, although a record low of −16 °F (−27 °C) was recorded in January 1984 and a record high of 105 °F (41 °C) was recorded in August 1955. Average monthly precipitation ranged from 2.84 inches (72 mm) in February to 4.83 inches (123 mm) in July.[25]
The county has a hot-summerhumid continental climate (Dfa) except in lower areas along the Raritan River from Bound Brook downstream, where the climate is nowhumid subtropical (Cfa). Thehardiness zone is 7a except in a few small, higher-elevation areas in the north, which are 6b.[28]
Somerset County, New Jersey – Racial and ethnic composition Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos may be of any race.
As of the2020 United States census, the county had 345,361 people, 122,606 households, and 88,540 families.[40] Thepopulation density was 1,144.3 inhabitants per square mile (441.8/km2). The 131,822 housing units had an average density of 436.77 per square mile (168.6/km2).[41] Theracial makeup was 61.0% White, 10.0% African American, 0.2% Native American, 18.5% Asian, and 2.2% from two or more races. Hispanics or Latinos of any race were 15.2% of the population.[42]
Of the 122,606 households, 21.5% had children under 18 living with them, 59.3% were married couples living together, 9.6% had a female householder with no husband present, 3.3% had a male householder with no wife present, and 27.8% were not families; 9.3% had someone living alone who was 65 or older. The average household size was 2.65 and the average family size was 3.16.
The county's age distribution was 21.5% under age 18, 8.4% from age 18 to 24, 36.3% from age 25 to 44, 17.6% from age 45 to 64, and 16.2% were age 65 or older. The median age was 42.2 years. The gender makeup was 49.2% male and 50.8% female. For every 100 females, there were 96.8 males.[43]
The median income for a household was $111,587, and for a family was $135,129. About 5.7% of the population were below thepoverty line, including 8.8% of those under 18 and 6.1% of those 65 or over.[44][45]
The2010 United States census counted 323,444 people, 117,759 households, and 84,669 families in the county. Thepopulation density was 1,071.7 per square mile (413.8/km2). There were 123,127 housing units at an average density of 408 per square mile (158/km2). The racial makeup was 70.06% (226,608)White, 8.95% (28,943)Black or African American, 0.17% (556)Native American, 14.11% (45,650)Asian, 0.03% (94)Pacific Islander, 4.13% (13,360) fromother races, and 2.55% (8,233) from two or more races.Hispanic or Latino people of any race were 13.01% (42,091) of the population.[7]
Of the 117,759 households, 35.9% had children under 18; 58.8% were married couples living together; 9.5% had a female householder with no husband present and 28.1% were not families. Of all households, 23.3% were made up of individuals and 8.5% had someone living alone who was 65 or older. The average household size was 2.71 and the average family size was 3.22.[7]
The county's age distribution was 25.0% under 18, 6.5% from 18 to 24, 26.4% from 25 to 44, 29.8% from 45 to 64, and 12.4% who were 65 or older. The median age was 40.2 years. For every 100 females, the population had 95.1 males. For every 100 females 18 and older, there were 91.8 males.[7]
Based onIRS data for the 2004 tax year, Somerset County taxpayers had the ninth-highest average federal income tax liability per return in the country. Average tax liability was $16,502, representing 16.8% ofadjusted gross income.[47]
The southeastern portion of Somerset County in Franklin Township includesDelaware and Raritan Canal State Park, which provides hiking, biking, and boating.[50] The parks commission operates five public golf courses.[49]Trump National Golf Club inBedminster, an exclusive golf club owned byDonald Trump,[51] that he used as a Summer White House during his presidency.[52]
Somerset County is governed by a five-memberboard of county commissioners, whose members are electedat-large to three-year terms of office on a staggered basis, with one or two seats coming up for election each year. At an annual reorganization meeting held on the first Friday of January, the board selects a director and deputy director from among its members.[53] In 2016, commissioners (then known as freeholders) were paid $21,902, and the commissioner director was paid an annual salary of $22,902.[54] The commissioners employ a full-time county administrator, Colleen Mahr,[55]who manages the day-to-day operations of the county government. The clerk of the county commissioners oversees the work of their offices. Department heads are appointed in accordance with statute and by resolution of the board. Somerset County currently has about 1,100 full-time and 140 part-time employees in 52 divisions.[53]
In June 2025, Elizabeth Graner was appointed to fill the commissioner seat expiring in December 2025 that had been held by Doug Singleterry until his resignation from office to take a position as a judge of theNew Jersey Superior Court.[66]
Democrats captured their first countywide office in 2018 since 1979, and in 2019 won a majority on the county commission for the first time since 1964. Republicans have not won a county-wide office since 2017.[67] Pursuant to Article VII Section II of theNew Jersey State Constitution, each county in New Jersey is required to have three elected administrative officials known as "constitutional officers." These officers are thecounty clerk andcounty surrogate (both elected for five-year terms of office) and thecounty sheriff (elected for a three-year term).[68] Constitutional officers, elected on a countywide basis, are:[57]
Sheriff Darrin J. Russo (D, Franklin Township, 2025)[71][72]
Surrogate Bernice "Tina" Jalloh (D, Franklin Township, 2025)[73][74]
The Somerset County Prosecutor is John P. McDonald, who was nominated by the Governor of New JerseyPhil Murphy and confirmed by theNew Jersey Senate in June 2022.[75] Somerset County is a part of Vicinage 13 of theNew Jersey Superior Court (along withHunterdon County andWarren County), which is seated at the Somerset County Courthouse inSomerville; the Assignment Judge is Michael V. Cresitello.[76]
In the2008,Barack Obama became the first Democratic presidential nominee to carry the county sinceLyndon Johnson in1964, and only the second since 1936. Obama won Somerset by a 6.1% margin overJohn McCain, with Obama carrying the state by 15.5% over McCain.[84] Somerset's growing Democratic trend at the presidential level has largely been spurred by the rapid growth of the overwhelmingly DemocraticFranklin Township in the county's southeast corner. The county has voted Democratic in every election since, with the 2020 election seeing Democrat Joe Biden win the largest share of the vote in the county for a Democrat since 1964, as the county voted more Democratic than the state as a whole for the first time since 1912. The county also voted to the left of the state in 2024, when Democratic nomineeKamala Harris won the county by 14%, despite winning New Jersey by just 6%.
As of October 1, 2021, there were a total of 262,410 registered voters in Somerset County, of whom 92,921 (35.4%) were registered asDemocrats, 66,455 (25.3%) were registered asRepublicans and 100,367 (38.2%) were registered asunaffiliated. There were 2,667 voters (1.0%) registered to other parties.[85] Among the county's 2010 Census population, 67.1% were registered to vote, including 75.% of those ages 18 and over.[86][87]
United States Senate election results for Somerset County, New Jersey1[88]
Raritan Valley Community College (RVCC),North Branch section ofBranchburg Township (public).[94]Rutgers University has a partnership with Raritan Valley Community College which allows students who have an accredited associate degree to complete a bachelor's degree by attending Rutgers classes at RVCC's North Branch campus. The degree completion program is specifically designed to cater to the transfer student looking to complete their bachelor's degree while staying close to home.[95]
Alma White College (which operated from 1921 to 1978) was a private college located in Zarephath.[97] Beginning in 1931 the college operated WAWZ 1380 on the AM radio dial. The station continued to 1984 after the school closed. The building is now occupied by Somerset Christian College.
Somerset Hills Learning Institute, founded in 1998 and located in Bedminster Township, educates children on the autism spectrum by utilizing the principles ofapplied behavior analysis.[99] In 2024, a localShopRite store started selling salads grown by and packed by students in the school's hydroponics career training program.[100]
Index map of Somerset County municipalities (click to see an index key)
Interactive map of municipalities in Somerset County.
The 21 municipalities in Somerset County (with 2010 Census data for population, housing units, and area) are listed below.[101] Otherunincorporated communities in the county are listed alongside their parent municipality (or municipalities, as the case may be). These areas includecensus-designated places (CDPs), which theUnited States Census Bureau created for enumeration purposes within atownship.[8] Other communities, historical areas, unincorporated areas, and enclaves that exist within a municipality are also listed.
Somerset County is served by a number of different routes. As of May 2010[update], the county had a total of 1,714.99 miles (2,760.01 km) of roadways, of which 1,370.80 miles (2,206.09 km) were maintained by the local municipality, 234.23 miles (376.96 km) by Somerset County and 109.96 miles (176.96 km) by theNew Jersey Department of Transportation.[103]
It was planned forInterstate 95 to run along theSomerset Freeway from its proposed southern end inHopewell Township,Mercer County to Franklin Township at I-287 in the 1960s. However, the plan was canceled in 1983. Part ofRoute 18 is theNew Brunswick border of Somerset.
NJ Transit provides bus service to thePort Authority Bus Terminal inMidtown Manhattan, as well as service to major cities in New Jersey and within Somerset County.[107] Ridewise provides three SCOOT shuttles[108] as well as DASH buses and CAT buses.[109][110]
^Governor Murphy Settles Central Jersey Debate,Governor of New JerseyPhil Murphy, press release dated August 4, 2023. "Governor Phil Murphy today signed S3206 to promote Central Jersey tourism.... The 'Central Jersey' region will be comprised of, at minimum, the counties of Hunterdon, Mercer, Middlesex, and Somerset."
^Willis, David P."'This is how wars start': Does Central Jersey include both Ocean and Union counties?",Asbury Park Press, February 20, 2023. Accessed March 31, 2024. "North Jersey is defined as Sussex, Warren, Morris, Passaic, Bergen, Essex and Hudson counties; South Jersey would be Burlington, Camden, Gloucester, Atlantic, Salem, Cumberland and Cape May counties. But for Central, things get a little tricky. It would include Hunterdon, Somerset, Union, Middlesex, Mercer, Monmouth, and Ocean counties."
^"Rankings".County Health Rankings & Roadmaps. RetrievedFebruary 1, 2018.
^Clemence, Sara."Home of the Week: Peapack Palace",Forbes, March 14, 2005. Accessed May 22, 2008. "It was once the country home of some of the 19th century's wealthiest families, and modern-day residents now include pharmaceuticals and chemicals barons."
^Home Page, Rutgers Cooperative Extension of Somerset County. Accessed January 11, 2017.
^abSordillo, Victor J.About Warren Township, Warren Township. Accessed October 1, 2013. "Once described as 'the greenest place in New Jersey', Warren Township residents and elected officials are working to keep its rural character and charm while recognizing that there will be growth due to the town's beauty, favorable property taxes and strategic location. Less than 35 miles to Manhattan makes Warren Township a favorite suburb for commuters to New York City."
^OverviewArchived October 4, 2013, at theWayback Machine, Green Brook Historical Society. Accessed October 1, 2013. "As the traffic through the corridor expanded, Green Brook Township developed from a quiet farming community, which it had been for nearly two hundred years, into the suburban community that it is today."
^History, Borough of Watchung. Accessed October 1, 2013. "Watchung was settled in the early eighteenth century and grew slowly until recent years. In 1960 the population was 3,312 and in 2000 it was 5,613."
^Glaberson, William."In Prosecutor's Rise and Fall, a Story of Ambition, Deceit and Shame. ",The New York Times, December 1, 1996. Accessed August 30, 2014. "When Nicholas L. Bissell Jr. put a gun in his mouth and pulled the trigger in a $20 room on a neon strip here, it was almost the cliche ending to an ambitious man's rise and fall. An unexceptional child of New Jersey's modest suburbs, he rose to become a feared prosecutor in Somerset County known for his swaggering assault on drug dealers."
^Welcome, Trump National Golf Club. Accessed October 6, 2013. "Greetings from Donald J. Trump: When I saw this beautiful piece of property in Bedminster, New Jersey, I knew that it deserved only the best."
^abcBoard of County Commissioners, Somerset County, New Jersey. Accessed July 24, 2025."Somerset County is governed and managed by a Board of County Commissioners, formerly known as the Board of Chosen Freeholders. The board consists of five members with one or two elected each year during the November general election from the County at large to serve three-year terms. County Commissioners elect from among themselves a Director who conducts their meetings.... Somerset County currently has 1,098 full-time employees and 144 part-time employees in 52 divisions."
^Deak, Mike."Bernards resident Elizabeth Graner fills Somerset County Board of Commissioners vacancy",Courier News, June 26, 2025. Accessed July 24, 2025. "Bernards Township resident Elizabeth Graner has been sworn in as a Somerset County’ Commissioner, filling the vacancy caused by Doug Singleterry resigning to become a Somerset County Superior Court judge. Graner, 55, becomes the fourth woman on the five-member Board of Commissioners, all of whom are Democrats.... She will run for Singleterry's unexpired term in the November general election."
^Surrogates, Constitutional Officers Association of New Jersey. Accessed July 24, 2025.
^Prosecutor John McDonald, Somerset County Prosecutor's Office. Accessed July 24, 2025. "John P. McDonald was sworn in as the Somerset County Prosecutor on July 1, 2022. He was nominated to the position by Governor Phil Murphy and confirmed by the New Jersey State Senate in June 2022."
^Biography, Congresswoman Bonnie Watson Coleman. Accessed January 3, 2019. "Watson Coleman and her husband William reside in Ewing Township and are blessed to have three sons; William, Troy, and Jared and three grandchildren; William, Kamryn and Ashanee."