🇺🇸 United States ZIP Code

STANDARD

98850

Rock Island

ZIP Code 98850 is a standard zip code serving Rock Island, Rock Island, Washington (WA), in Douglas County, United States. It has an estimated population of 1,543 with a median household income of $32,500. The area falls within the America/Los_Angeles timezone.

Median Household Income vs. National Average

Location

Country: 🇺🇸 United States
State / Province: Washington (WA)
County: Douglas
City: Rock Island
Timezone: America/Los_Angeles

Coordinates

Latitude: 47.370600
Longitude: -120.137800

Geographic Details

Land Area: 22.70 mi²
Water Area: 2.73 mi²
Population Density: 68.0 people per mi² (45th percentile)
Bounding Box: 47.391415°N, 47.223652°S, -120.004667°E, -120.192264°W

With 1,543 residents spread across 22.70 square miles, this area has a population density of 68.0 people per square mile.

Demographics

1,543

Population

35th percentile

$32,500

Median Income

10th percentile

$151,500

Median Home Value

60th percentile

22.70 mi²

Land Area

The median household income in 98850 is $32,500, and the median home value is $151,500. This is below the national average for household income.

Housing

596

Total Units

522

Occupied Units

87.6%

Occupancy Rate

Similar ZIP Codes in Washington

ZIP codes with similar median household income in Washington.

98339

Port Hadlock

$30,932

98550

Hoquiam

$36,036

98856

Twisp

$33,967

99001

Airway Heights

$36,875

98439

Lakewood

$33,445

98948

Toppenish

$35,210

98901

Yakima

$35,738

98902

Yakima

$36,943

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.