ZIP Codes of Washington County, ID

Population & People
Population & People
Total Population
11,138
Household Income
Household Income
Median Income
$60,696
Housing
Housing
Total Housing Units
4,627
Business & Economy
Business & Economy
Total Businesses
222
Employment
Employment
Employment Rate
45.10%
Education
Education
Bachelor's Degree+
20.59%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 3 ZIPs in this county.
Data Last Updated: July 1, 2026
ZIP Codes:3 ZIP Codes (3 Standard, 0 PO Box, 0 Unique) [See All]
Area Codes:208 / 986
Timezone:Mountain (GMT -07:00)
Local Time:11:53:16 PM
Population:11,138 [See All]
FIPS:16087
Land Area:1,408 sq mi
Water Area:20 sq mi
Coordinates:44.4778, -116.8060
Quick Link:
https://www.zip-codes.com/county/id-washington.asp
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Idaho's #28 most populous county
11,138 residents across 3 ZIPs — #28 of 46 Idaho counties.

Standout ZIPs in this County


Most Populous
Weiser · 9,176 people
82.4% of county total
Highest Income
Cambridge · $65,625 median
1.1× county average
Largest Land Area
Weiser · 561.7 sq mi
Spans the most ground
Fastest Growth
Weiser · 6.4% (10-yr)
8,628 → 9,176 residents
Most Educated
Weiser · 20.5% bachelor's+
1,299 of 6,350 adults 25+

Things worth knowing about Washington County


11,138 residents live across 3 ZIPs covering 1,408 sq mi, served by 3 distinct USPS-recognized cities.

Population moved from 10,039 to 11,138 from 2014 to 2024 — a +10.9% change. 3 ZIPs gained residents, 0 lost.

The county's wealthiest ZIP 83610 (Cambridge, $65,625 median) and poorest ZIP 83672 (Weiser, $51,045) are 19.3 miles apart — a 1.3× income gap across local geography.

Median home values vary 1.2× across this county — from $272,800 in 83672 (Weiser) to $315,700 in 83645 (Midvale).

Density varies across the county — from 2 people/sq mi in 83645 (Midvale) to 16 in 83672 (Weiser).

Educational attainment ranges from 20.5% bachelor's+ in 83672 (Weiser) to 21.4% in 83610 (Cambridge) — the breadth of educational profiles across the area.

Within Idaho, this is the #28 most populous of 46 counties and ranks #41 for median household income with the #23 fastest decade growth .

Weighted by population, the typical household earns about $53,595 across the county — reflecting what a typical resident sees, not a simple ZIP average.

20.6% of adults age 25+ hold a bachelor's degree or higher (1,613 of 7,834 reporting).

3 Standard delivery, 0 PO Box only, 0 single-entity Unique ZIPs serve this county.

Stories about Washington County


Big & sparse

A frontier county — vast land area with only a few residents per square mile. Daily life looks very different here than in the country's denser counties.

Total area
1,408
square miles
Avg density
7.9
people per sq mi
Population
11,138
across 3 ZIPs
Weiser
561.7 sq mi
9,176 residents
Midvale
465.4 sq mi
970 residents
Cambridge
381.1 sq mi
992 residents

Single-ZIP anchor

One ZIP holds the majority of this county's population — a sign of a county built around a single city or town.

Weiser

All ZIP Codes in Washington County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
83672WeiserStandard9,176$51,045561.76.4%
83610CambridgeStandard992$65,625381.110.7%
83645MidvaleStandard970$65,417465.488.3%

Adjacent & Nearby Counties