Data Last Updated: April 1, 2025

Columbia County, WA ZIP Codes

ZIP Codes: Shows how many general ZIP Codes, PO Boxes, Unique (Business), and Multi County ZIP Codes are associated with Columbia, WA.	4 ZIP Codes (1 General, 1 PO Box, 0 Unique, & 2 Multi County) [More Details]
Area Code: The Telephone Area Code that are associated with Columbia, WA. Area Codes are used in the North American Numbering Plan (NANP) to facilitate phone routing. There are approximately 350 area codes in use in the United States.	509
Timezone: Time zone designation within the U.S. Please note that not all areas in the U.S. observe daylight saving time which can affect actual local time for this city. There are 7 standard time zones which are, from west to east: Hawaii-Aleutian, Alaska, Pacific, Mountain, Central, Eastern, Atlantic. Also included in U.S. Territories are Samoa, Guam and Palau.	Pacific
Local Time: The current local time for each timezone. If more than 1 time zone for this area, all local times will be shown. Counties can cross timezones, so more than 1 may be shown.	12:00:00 AM
Population: The population of Columbia, WA from the U.S. Census 2020. Included are U.S. Citizens, permanent residents, temporary migrants, and undocumented individuals. The total population represents people who live in the city, not just those present while the Census was being completed.	3,952 [More Details]
FIPS: FIPS stands for Federal Information Processing Standards, which are a set of publicly announced standards for computer systems. A county FIPS code is a unique numeric identifier for a county in the United States, assigned by the National Institute of Standards and Technology (NIST). County FIPS codes have five digits, with the first two digits identifying the state and the last 3 indicating the county.	53013
CBSA: A Core Based Statistical Area (CBSA) is the recognized term for a region that functions around an urban core with a population of at least 10,000 people, according to the standards set by the Office of Management and Budget (OMB) in 2000. A CBSA is divided into two subsets: Metro and Micro, and these classifications are determined by population density. A Micro area is identified by a population ranging between 10,000 to 50,000, while a Metro area is defined as having a population that exceeds 50,000.	None
Land Area: The approximate amount of land area covered by Columbia, WA in square miles. The Land Area provided by the Census Bureau is based on geographic boundaries that include the mainland, islands, inland, coastal, Great Lakes, and territorial waters associated with each city.	869 square miles
Water Area: The approximate amount of water area covered by Columbia, WA in square miles. Calculations by the Census Bureau for Water Area take into account inland bodies of water, coastal regions, Great Lakes, and territorial sea waters. This encompasses features such as lakes, reservoirs, rivers, and coastal water bodies.	5 square miles
Coordinates: The latitude/longitude centroid coordinates for Columbia County, WA.	-117.907756, 46.297513
Quick Link: Copy the direct link to the Columbia, WACounty page and use anywhere you like!	https://www.zip-codes.com/county/wa-columbia.asp

Columbia, WA ZIP Code Boundaries

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Columbia County, WA Covers 4 ZIP Codes

ZIP Code	Classification	City	Population	% of Population
ZIP Code 99328	General	Dayton	3,620	91.60%
ZIP Code 99347 *	General	Pomeroy	2,342	--
ZIP Code 99359	P.O. Box	Starbuck	155	3.92%
ZIP Code 99361 *	General	Waitsburg	1,908	--

* Indicates a Multi County ZIP Code. These ZIP Codes partially cross over into Columbia, WA, but will mostly cover area in a different County. Not included in % of Population calculations.

Important Columbia, WA Information

Columbia County, WA Covers 4 ZIP Codes. This includes 1 General ZIP Codes, 1 PO Box ZIP Codes, and 0 Unique (reserved for Business and Volume Mail Receivers). There are also 2 Multi County ZIP Codes. These records are assigned a different primary county, but they partially cover area in Columbia County.

The population for Columbia County is 3,952, according to the U.S. Census. Population Density is 4.55 persons per square mile. With 2,190 Housing Units, the Average Household Size is 2.20 persons. There are 1,765 Family Households with an Average Family Size of 3.03 persons. 7.37% of the population is without Health Insurance. The 52.77% Employment Rate is 7.03% above the national average of 59.8%.3,097 people aged 25+ have some educational achievement, with 27.22% (or 843 people) having attained a Bachelor's Degree or higher.More Demographics are available below.

509 is the only area code for this area. Columbia is also located in the Pacific timezone and the current local time is shown above.

ZIP Codes in Columbia, WA have 1,693 Residential mailboxes and 177 Business mailboxes.There are 114 businesses with a total of 987 employees. That is an average of 8.7 employees per business. Annual payroll for these businesses is $44,182,000. Other Demographics

Columbia County Demographic Profile

Population & People

Total Population

3,952

Income

Median Household Income

$71,528

Housing

Total Housing Units

2,190

Health

Without Healthcare Coverage

7.37%

Business & Economy

Total Businesses

114

Families

Total Households

1,765

Employment

Employment Rate

52.77%

Education

Bachelor's Degree or Higher

27.22%

Total Population: Total number of people from the 2020 U.S. Census for Columbia, WA. This reflects the exact count of this area at that point in time, not future estimates, regardless of citizenship or immigration status. It is intended to count all persons living within the geographic area, not just those present on the day of the census.	3,952
Current Population Estimate: This field gives the estimated household population for All ZIP Codes in Columbia, WA. This is derived from known delivery information, household occupancy rates, household size, and more to come up with an accurate estimation for the current population. IMPORTANT: This does not include population totals for persons in nursing homes, correctional facilities, or other institutions. This is an estimation of the household population based on US Postal Service delivery information.	3,741
Total Households: Total number of Households from the 2020 U.S. Census for Columbia, WA. A Household includes everyone living in a residential housing unit. This includes families, roommates in a single residence, or a person living alone.	1,765
Total Housing Units: The total number of Housing Units is the number of occupied units + the number of vacant units. Ownership is defined by whether the unit is occupied by an owner or by a tenant. Owner occupancy means that the owner lives in the unit. This value comes from the 2020 U.S. Census and is not a projection or estimate.	2,190
Average Household Size: The Average Household Size, is obtained by dividing the number of people in Households (excluding those in group quarters, nursing home, prisons, and dorm rooms) by the number of Households. A Household includes everyone living in a residential unit. Those who do not live in a household are classified as living in group accommodation. This value is an estimate from the U.S. Census ACS (American Community Survey) and is updated yearly.	2.20
Average Family Size: Average Family Size is calculated by dividing the number of people in a Family Household by the number of Family Households. The U.S. Census Bureau defines family households as households consisting of two or more individuals who are related by birth, marriage, or adoption. They also may include other unrelated people. Non-family households consist of people who live alone or who share their residence with unrelated individuals. The Average Family Size only looks at the households classified as Family Households. This value is an estimate from the U.S. Census ACS (American Community Survey) and is updated yearly.	3.03

Other Columbia Demographics

# Residential Mailboxes: The number of active residential delivery mailboxes and centralized units. This excludes PO Boxes and all other contract box types.	1,693
# Business Mailboxes: The number of active business delivery mailboxes and centralized units. This excludes PO Boxes and all other contract box types.	177
Total Delivery Receptacles: The total number of delivery receptacles. This includes curb side mailboxes, centralized units, PO Boxes, NDCBU, and contract boxes. This count is for Residential and Business combined.	2,200
Single Family Delivery Units: Total count of single family mail delivery receptacles; generally analogous to homes.	1,497
Multi Family Delivery Units: Total count of multifamily mail delivery receptacles; generally analogous to apartments.	4

# of Businesses: The total number of Business Establishments. Data taken from Business Census 2023.	114
1st Quarter Payroll: The total payroll for the first quarter. Data taken from Business Census 2023.	$10,942,000
Annual Payroll: The total annual payroll . Data taken from Business Census 2023.	$44,182,000
# of Employees: The total number of employees for all ZIP Codes in this City. Data taken from Business Census 2023.	987

Sum of all ZIP Codes assigned Columbia, WA as their primary County.

References

U.S. Postal Service [Last Updated: 4/1/2025], https://www.usps.com
ZIP-Codes.com Internal Data Creation [Last Updated: 4/1/2025], https://www.zip-codes.com
U.S. Geological Survey [Updated as needed], https://www.usgs.gov
U.S. Census [Updated Yearly], https://www.census.gov
U.S. Census 2020 [Decennial] [Last Updated: 5/25/2023], https://www.census.gov