Mountainside
A borough in Union County, New Jersey — population 6,876 as of 2020.
Home city
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stops being your city.
Mountainside takes over news, events and the map.
Tonight
54°F
Partly Cloudy1% precip
Sunday
64°F
Chance Rain Showers54% precip
Sunday Night
56°F
Chance Rain Showers then Mostly Cloudy54% precip
Monday
68°F
Mostly Sunny1% precip
News around Union County
WRNJ Radio
September 25Person fatally struck by NJ Transit train in Union County
PLAINFIELD, N.J. (Union County) — A person was fatally struck by an NJ Transit train at the Plainfield station early Friday morning, according to NJ Transit. At approximately 5:40 a.m., …
Public SafetyIn and around Mountainside
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Mountainside by the numbers
Population
6,876Population figure, 2020
Households & income
- Area
- 4 sq mi (10.35 km²), 0.05 sq mi water
- Median age
- 48
- Households
- 2,508
- Persons per household
- 2.8
- Median household income
- $211,538
- Median house value
- $810,300
Municipal office
- Office
- MUNICIPAL CLERK
- Address
- 1385 US HIGHWAY 22, MOUNTAINSIDE, NJ 07092