Lewis County area

Population and density of Lewis County

The Census Bureau estimates that 88,062 people lived in Lewis County on July 1, 2025. That ranks #686 of 3,222 county equivalents nationally and #15 of 39 in Washington. Since the April 1, 2020 estimates base of 82,144, the population has grown by 5,918 (+7.2%), compared with +3.8% for Washington as a whole.

With 2,402.8 square miles of land, that is 37 people per square mile (14 per km²), placing Lewis County #1,835 nationally for density and #21 in Washington. The median county equivalent has 47 people per square mile; the Washington median is 39. Put another way, there are about 17 acres of land per resident.

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in Lewis County

9 incorporated places lie at least partly in Lewis County. Together they are home to 36,015 people (40.9%); the other 52,047 (59.1%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Centralia city, with 19,375 residents in the county. The county seat, Chehalis city, has 7,764 residents. Among places with at least 1,000 residents in 2020, Winlock city grew fastest since then (+45.1%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Lewis County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Lewis County is a central county of the Centralia, WA Micropolitan Statistical Area. Lewis County is the area’s only county equivalent, so the micro area has the same 2,402.8 square miles of land. By combined land it ranks #63 of 542 micropolitan areas, and #55 by population. It belongs to the Seattle-Tacoma, WA Combined Statistical Area.

ZIP codes

24 ZIP Code Tabulation Areas have land in Lewis County; 21 of them have most of their land inside the county, and the others mainly cover neighboring areas.

983049833698355983569836198377985319853298533985389853998542985449856498565985689857098572985799858298585985919859398596

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Lewis County

Lewis County shares a land border with 8 county equivalents. It has more land than 7 of them. The largest neighbor is Yakima County (4,294.5 mi²) and the smallest is Wahkiakum County (262.9 mi²). Together with its neighbors, Lewis County forms a block of 14,985.8 mi² of land, of which it holds 16%.

How big is Lewis County compared with U.S. states?

Lewis County has more land than 2 of the 50 states. It is about 1.2 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 2 times as much land (4,842.5 mi²). Washington’s county land could hold about 28 areas the size of Lewis County.

Another way to picture it: the same land area would fill a square about 49 miles (78.9 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about Lewis County?

Lewis County has more land than 2,995 of the other 3,221 county equivalents in the dataset.

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Lewis County at #241 nationally by total area, 14 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 1.4%, compared with a national county-equivalent median of 1.2% — 0.2 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Lewis County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.