Mountainside is a borough in Union County, in the U.S. state of New Jersey. The borough is located on a ridge in northern-central New Jersey, within the Raritan Valley and Rahway Valley regions in the New York metropolitan area. As of the 2020 United States census, the borough's population was 7,020, an increase of 335 (+5.0%) from the 2010 census count of 6,685, which in turn reflected an increase of 83 (+1.3%) from the 6,602 counted in the 2000 census. Mountainside was incorporated as a borough on September 25, 1895, from portions of Westfield Township, based on the results of a referendum held the previous day. New Jersey Monthly magazine ranked Mountainside as its 16th best place to liv…

Official town website ↗

From Wikipedia, licensed CC BY-SA 4.0 · facts via Wikidata (CC0)

How Mountainside ranks

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#6Most trails in NJ #21Most active in NJ #25Fewest smokers in NJ All NJ rankings →

Town numbers

ZIP code07092

Area code908

Living in Mountainside

Housing in Mountainside

$1.06M▲ 3.8% in a year Typical home value · Zillow

The typical Mountainside home is worth about $1,065,000, up 3.8% in a year, 83% above the New Jersey typical home.

A strong seller's market

Buyer’sBalancedSeller’s

Days on market13

Sale-to-list107.1%

Sold in May7

Zillow Home Value Index · Redfin Data CenterHousing market →

Safety in Mountainside

A⁺

Safety Grade A+

Mountainside reports less crime per resident than 95% of the U.S. towns and cities we grade.

Violent crime per 1,000

Mountainside 0.1

New Jersey 2

U.S. 3.3

Property crime per 1,000

Mountainside 5.1

New Jersey 12.7

U.S. 15.5

FBI crime data, 2025 · crimes reported to policeCrime & safety →

Work & commute in Mountainside

Full picture →

Most working residents leave Mountainside for work: only 5% work in town. The top destinations are New York (16%), Newark (5%) and Elizabeth (3%). Half commute less than 12 miles.

New York, NY

16%

Newark

Elizabeth

Westfield

5%Work in townlive and work in Mountainside 12 miWhere do people commute?the commute map 5,124Jobs based herea job hub

Census LEHD 2023 · ACSWork & commute in Mountainside →

Health in Mountainside

A⁺

Health Grade A+

Healthier than 99% of U.S. towns on seven CDC estimates.

Compared with New Jersey

19better than NJ·1worse

of 32 measures CDC estimates. The other 12 are too close to call.

Conditions 3▲ 1▼ 8 close Habits 3▲ 1 close Care 4▲ 3 close Mind 5▲ 0 close Everyday needs 4▲ 0 close

BetterToo close to callWorse

What stands out

2.9%Fewer older adults who have lost all their teethNJ 9.6% · better 6%Fewer adults facing food insecurityNJ 14.3% · better 10.5%More adults who have had cancerNJ 7.5% · worse

Care nearby

Overlook Medical CenterSummit · 2.2 mi · ER

Irvington Community Health CenterIrvington · 7.2 mi · sliding-scale fees

Primary careNo shortage

DentalNo shortage

Mental healthNo shortage

CDC PLACES 2025 · modeled estimates for adults · CDC's estimate for Mountainside · CMS · HRSAHealth in Mountainside →

Natural hazards in Mountainside

Low

Expected storm and flood damage is higher than in 37% of U.S. communities.

🌊 Inland flooding🏚️ Earthquakes

15Does Mountainside flood?paid flood claims since 1979 9Disasters that paid out herefederal disasters sent FEMA money to Mountainside MapMountainside vs. its neighborsnearby towns shaded by rating

FEMA National Risk Index December 2025 · OpenFEMANatural hazards in Mountainside →

Climate in Mountainside

Full climate →

Mountainside has chilly winters and warm summers, with plenty of rain. A typical July afternoon reaches 86°, a January night drops to 23°, and about 24 inches of snow falls in a normal winter.

42° / 25°Winter

62° / 40°Spring

84° / 62°Summer

66° / 45°Fall

How much snow does Mountainside get?About 24 inches a winter.Rain & snow →When is the first frost?Around Oct 27, with the last in spring around Apr 18.Frost dates →Is it warmer than it used to be?+2.2° vs. the 20th century.Then & now →

NOAA U.S. Climate Normals, 1991–2020Climate in Mountainside →

Schools in Mountainside

All Mountainside schools →

School Grade A

The public schools Mountainside’s kids attend outperform 91% of New Jersey’s districts on state tests. Among towns with similar incomes, they rank near the top.

#48Best public schoolsof 457 in NJ

DistrictMountainside School DistrictSchools4

Beechwood SchoolElementary · Grades PK–2 · 265 students Primrose School at MountainsideElementary · Grades PK–K · 10 students Deerfield Elementary School AMiddle · Grades 3–8 · 483 students Kohler AcademyOther · Grades PK–12 · 46 students

School data from the U.S. Department of Education (NCES, EDFacts). The School Grade is our own summary of state test results, graded within NJ. Ratings are from neighbors.