Mountainside, New Jersey

Mountainside population, 2020 to 2024

Mountainside added 236 residents from July 2020 to July 2024, a change of +3.4%. In the latest year it moved by +189. Among 194 New Jersey places of 5,000 or more, that growth ranks 40th; the median place changed by +1.8%. The median place of 5,000+ in New Jersey has 11,231 people, so Mountainside is 64% of it.

Mountainside covers 4.00 square miles of land and 0.05 of water, for 1,807 people per square mile of land. The median New Jersey place of 5,000+ has 4,474, so Mountainside is less dense than the typical town.

What county Mountainside is in

All of Mountainside's residents live in Union County, which had 594,160 residents in 2024. Mountainside holds 1.2% of the county's population. The shaded shape is on the map above; dots mark the eight nearest places.

ZIP codes in Mountainside

1 ZIP Code Tabulation Area (ZCTA) overlaps Mountainside by at least 10% of the ZCTA's or the borough's land: 07092. ZCTAs are Census approximations of USPS ZIP code delivery areas. The list comes from the 2020 ZCTA to place relationship file, so a borough that annexed land after 2020 may reach into ZIP codes not listed here.

Where Mountainside is

The Census internal point of Mountainside is at 40.680700, -74.360300. Trenton, the capital, is 38.0 miles SSW in a straight line. The nearest larger place is Westfield, NJ (32,050 people), 2.2 miles away. The nearest city of 100,000 or more is Elizabeth, NJ, 8.8 miles away.

Daylight in Mountainside

At 40.68° N, Mountainside gets about 15 h 06 min of daylight around the June solstice and 9 h 15 min around the December solstice, a swing of 5 h 50 min. Figures are sunrise to sunset from the SunCalc model for June 21 and December 21, 2026.

Places near Mountainside

The eight nearest incorporated places of 1,000+ in New Jersey, measured between internal points. The closest is Westfield, 2.2 miles away, with 32,050 people.