Mercer Island, Washington

Mercer Island population, 2020 to 2024

Mercer Island lost 448 residents from July 2020 to July 2024, a change of -1.7%. In the latest year it moved by +238. Among 125 Washington places of 5,000 or more, that growth ranks 114th; the median place changed by +2.6%. The median place of 5,000+ in Washington has 18,148 people, so Mercer Island is 1.4 times that size.

Mercer Island covers 6.38 square miles of land and 6.52 of water, for 3,966 people per square mile of land. The median Washington place of 5,000+ has 2,694, so Mercer Island is denser than the typical town.

What county Mercer Island is in

All of Mercer Island's residents live in King County, which had 2,340,211 residents in 2024. Mercer Island holds 1.1% of the county's population. The shaded shape is on the map above; dots mark the eight nearest places.

ZIP codes in Mercer Island

1 ZIP Code Tabulation Area (ZCTA) overlaps Mercer Island by at least 10% of the ZCTA's or the city's land: 98040. ZCTAs are Census approximations of USPS ZIP code delivery areas. The list comes from the 2020 ZCTA to place relationship file, so a city that annexed land after 2020 may reach into ZIP codes not listed here.

Where Mercer Island is

The Census internal point of Mercer Island is at 47.564000, -122.231200. Olympia, the capital, is 48.1 miles SW in a straight line. The nearest larger place is Bellevue, WA (154,377 people), 4.2 miles away.

Daylight in Mercer Island

At 47.56° N, Mercer Island gets about 15 h 59 min of daylight around the June solstice and 8 h 26 min around the December solstice, a swing of 7 h 33 min. Figures are sunrise to sunset from the SunCalc model for June 21 and December 21, 2026.

Places near Mercer Island

The eight nearest incorporated places of 1,000+ in Washington, measured between internal points. The closest is Newcastle, 3.8 miles away, with 13,072 people.