🇺🇸 United States ZIP Code

STANDARD

51535

Griswold

ZIP Code 51535 is a standard zip code serving Griswold, Griswold, Iowa (IA), in Cass County, United States. It has an estimated population of 1,923 with a median household income of $45,865. The area falls within the America/Chicago timezone.

Median Household Income vs. National Average

Location

Country: 🇺🇸 United States
State / Province: Iowa (IA)
County: Cass
City: Griswold
Timezone: America/Chicago

Coordinates

Latitude: 41.235000
Longitude: -95.137500

Geographic Details

Land Area: 130.16 mi²
Water Area: 0.01 mi²
Population Density: 15.0 people per mi² (15th percentile)
Bounding Box: 41.317843°N, 41.158475°S, -94.945544°E, -95.308985°W

With 1,923 residents spread across 130.16 square miles, this area has a population density of 15.0 people per square mile.

Demographics

1,923

Population

40th percentile

$45,865

Median Income

45th percentile

$91,500

Median Home Value

30th percentile

130.16 mi²

Land Area

The median household income in 51535 is $45,865, and the median home value is $91,500.

Housing

900

Total Units

793

Occupied Units

88.1%

Occupancy Rate

Similar ZIP Codes in Iowa

ZIP codes with similar median household income in Iowa.

51004

Anthon

$43,333

52654

Wayland

$48,594

52565

Keosauqua

$41,477

52653

Wapello

$47,500

50662

Oelwein

$40,385

52049

Garnavillo

$52,188

50317

Des Moines

$44,744

52035

Colesburg

$46,667

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.