Newcastle, Washington

Newcastle population, 2020 to 2024

Newcastle lost 73 residents from July 2020 to July 2024, a change of -0.6%. In the latest year it moved by +195. Among 125 Washington places of 5,000 or more, that growth ranks 97th; the median place changed by +2.6%. The median place of 5,000+ in Washington has 18,148 people, so Newcastle is 72% of it.

Newcastle covers 4.43 square miles of land and 0.03 of water, for 2,951 people per square mile of land. The median Washington place of 5,000+ has 2,694, so Newcastle is close to the typical town.

What county Newcastle is in

All of Newcastle's residents live in King County, which had 2,340,211 residents in 2024. Newcastle holds 0.6% of the county's population. The shaded shape is on the map above; dots mark the eight nearest places.

ZIP codes in Newcastle

2 ZIP Code Tabulation Areas (ZCTAs) overlap Newcastle by at least 10% of the ZCTA's or the city's land: 98056, 98059. 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 Newcastle is

The Census internal point of Newcastle is at 47.531500, -122.165600. Olympia, the capital, is 48.5 miles SW in a straight line. The nearest larger place is Mercer Island, WA (25,302 people), 3.8 miles away. The nearest city of 100,000 or more is Renton, WA, 3.9 miles away.

Daylight in Newcastle

At 47.53° N, Newcastle 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 32 min. Figures are sunrise to sunset from the SunCalc model for June 21 and December 21, 2026.

Places near Newcastle

The eight nearest incorporated places of 1,000+ in Washington, measured between internal points. The closest is Mercer Island, 3.8 miles away, with 25,302 people.