🇺🇸 United States ZIP Code

STANDARD

98555

Lilliwaup

ZIP Code 98555 is a standard zip code serving Lilliwaup, Lilliwaup, Washington (WA), in Mason County, United States. It has an estimated population of 599 with a median household income of $30,653. The area falls within the America/Los_Angeles timezone.

Median Household Income vs. National Average

Location

Country: 🇺🇸 United States
State / Province: Washington (WA)
County: Mason
City: Lilliwaup
Timezone: America/Los_Angeles

Coordinates

Latitude: 47.512800
Longitude: -123.063100

Geographic Details

Land Area: 20.39 mi²
Water Area: 0.08 mi²
Population Density: 29.0 people per mi² (30th percentile)
Bounding Box: 47.606849°N, 47.457898°S, -122.982321°E, -123.131121°W

With 599 residents spread across 20.39 square miles, this area has a population density of 29.0 people per square mile.

Demographics

599

Population

15th percentile

$30,653

Median Income

10th percentile

$166,300

Median Home Value

65th percentile

20.39 mi²

Land Area

The median household income in 98555 is $30,653, and the median home value is $166,300. This is below the national average for household income.

Housing

850

Total Units

321

Occupied Units

37.8%

Occupancy Rate

Similar ZIP Codes in Washington

ZIP codes with similar median household income in Washington.

98402

Tacoma

$31,500

99207

Spokane

$32,183

98339

Port Hadlock

$30,932

98104

Seattle

$26,637

98635

Lyle

$35,027

98439

Lakewood

$33,445

98586

South Bend

$33,966

98547

Grayland

$27,924

Frequently Asked Questions

What information is available for each ZIP code?

Each ZIP code page shows city, state, county, geographic coordinates, timezone, population, median household income, median home value, housing units, land area, population density, commute time, educational attainment, area codes, and ZIP code type (Standard, PO Box, or Unique).

What are the different types of ZIP codes?

There are three types of ZIP codes: Standard (residential and commercial delivery areas), PO Box (assigned to post office box sections), and Unique (assigned to a single high-volume address like a government agency or large company). Standard ZIP codes are the most common.

How often is ZIP code data updated?

ZIP code assignments are updated quarterly by the USPS. Demographic data comes from the US Census Bureau's American Community Survey (ACS), which releases new 5-year estimates annually. ZipFYI updates its data to reflect the latest available information.

What is population density and why does it matter?

Population density measures the number of people per square mile in a ZIP code area. It helps identify urban vs. rural areas, affects real estate values, impacts service availability, and is used in market analysis. Dense urban ZIP codes may have 50,000+ people per square mile.

How are ZIP code boundaries determined?

ZIP code boundaries are determined by the USPS based on mail delivery routes, not political or geographic boundaries. They follow carrier routes and may cross city, county, or even state lines. Boundaries can change when the USPS reorganizes delivery operations.

What does median household income tell me about a ZIP code?

Median household income is the middle value when all household incomes in a ZIP code are sorted. Half of households earn more and half earn less. It is a better indicator of typical earnings than average income, which can be skewed by very high or very low outliers.