• county
  • FIPS 16087
  • Largest town: Weiser

Washington County, Idaho

Washington County had 11,539 residents in the Census Vintage 2024 estimate, on 1,452.9 square miles of land. It ranks 29th of 44 in Idaho by population and 20th by land area.

Population
11,539
#29 of 44 in Idaho · #2,315 in US
Area
1,452.9 sq mi
#20 of 44 in Idaho · #412 in US
Density
7.9 / sq mi
#25 of 44 in Idaho · #2,647 in US
Median household income
$57,369
#41 of 44 in Idaho · #2,095 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

Washington County within Idaho. Pin: Boise.

Measure from here

Tools and pages that start from Washington County

Washington County population, land area and income

Washington County had 11,539 residents in the Census Vintage 2024 estimate, on 1,452.9 square miles of land. It ranks 29th of 44 in Idaho by population and 20th by land area. That works out to 7.9 people per square mile, below the US average of 96.3, and in the bottom quarter nationally.

The median county-equivalent in Idaho has 15,019 residents; Washington County is somewhat smaller.

Its SAIPE 2023 median household income of $57,369 is below the national county median among 3,143 counties with an estimate.

National rank among 3,144

Population

11,539

3144th1st

2315th of 3,144 (US)

Land area

1,453 sq mi

3144th1st

412th of 3,144 (US)

Density

7.9 / sq mi

3144th1st

2647th of 3,144 (US)

Median household income

$57,369

3143rd1st

2095th of 3,143 (US)

Rank within Idaho (44)

Population

11,539

44th1st

29th of 44 (ID)

Land area

1,453 sq mi

44th1st

20th of 44 (ID)

Density

7.9 / sq mi

44th1st

25th of 44 (ID)

Median household income

$57,369

44th1st

41st of 44 (ID)

How Washington County's population changed since 2020

Washington County gained 979 residents between the July 2020 and July 2024 estimates, a rise of 9.3%. That ranks 12th of 44 in Idaho for growth. The median Idaho county changed by +7.2%, and the state as a whole by +8.2%.

Since the April 2020 estimates base, Washington County recorded 502 births and 708 deaths, a natural change of -206. Net international migration added +245 and net domestic migration, people moving to or from other US counties, came to +1,011. The largest single component was domestic migration, which added 1,011 people.

10.6k202010.9k202111.2k202211.5k202311.5k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
502
Deaths
708
Net international migration
+245
Net domestic migration
+1,011
Change, July 2023 to July 2024
+31

Where Washington County is

The Census internal point of Washington County is at 44.448200, -116.797800. It sits in UTM zone 11N. The map shades Idaho's 44 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Washington County outlined. Dots are towns of 1,000+ people with residents in it.

Madison County: +5.0%Idaho County: +8.0%Benewah County: +9.9%Gooding County: +3.4%Lincoln County: +8.2%Minidoka County: +4.7%Custer County: +7.7%Boundary County: +15.6%Lemhi County: +5.5%Twin Falls County: +6.8%Franklin County: +9.5%Oneida County: +9.0%Gem County: +13.4%Shoshone County: +6.6%Fremont County: +7.3%Clearwater County: +4.6%Kootenai County: +9.0%Cassia County: +4.9%Blaine County: +3.8%Clark County: +0.1%Jerome County: +7.4%Bonner County: +13.8%Elmore County: +3.7%Caribou County: +3.2%Bonneville County: +7.1%Jefferson County: +12.1%Power County: +6.3%Lewis County: +5.8%Nez Perce County: +1.7%Ada County: +7.5%Adams County: +12.9%Valley County: +7.9%Bingham County: +5.8%Bannock County: +4.3%Owyhee County: +6.2%Washington County: +9.3%Latah County: +6.4%Teton County: +10.2%Camas County: +15.0%Boise County: +12.0%Bear Lake County: +6.5%Butte County: +5.9%Canyon County: +14.5%Payette County: +8.1%
Change 2020 to 2024
  1. < +4.7%
  2. < +6.4%
  3. < +7.7%
  4. < +9.9%
  5. ≥ +9.9%
no data

Orange pin: Washington County internal point. Dark pin: Boise.

Internal point

Decimal
44.448200, -116.797800
DMS
44°26'53.52"N 116°47'52.08"W
UTM
11N 516088.7E 4921675.3N
Geohash
9ruuy5w3w
Plus code
85P5C6X2+7V

Towns in Washington County

One incorporated place of 1,000+ people has residents in Washington County, 6,112 people together, or 53% of the county. Each figure counts only the part of the town inside Washington County; towns marked "part" extend into another county. The largest is Weiser with 6,112.

  1. 01Weiser6,112
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Washington County

The Census 2024 county adjacency file lists 5 neighbors for Washington County, including 2 across a state line. The most populous is Malheur County, OR, with 32,315 residents. Distances run between Census internal points in a straight line.

Distance to Boise and the nearest big city

Boise is 64.3 miles SSE of Washington County's internal point in a straight line. The nearest place of 100,000 or more is Nampa, ID (population 117,350), 60.8 miles away. The nearest place of 10,000 or more is Ontario, OR (population 11,957), 30.6 miles away.

Washington County FIPS code

The FIPS code of Washington County is 16087: state code 16 for Idaho plus county code 087. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $57,369.

Questions people ask

What is the population of Washington County, Idaho?

The Census Vintage 2024 estimate for July 1, 2024 is 11,539. That is up 979 people (9.3%) from the July 2020 estimate of 10,560.

What is the FIPS code of Washington County?

16087. The first two digits (16) are Idaho; the last three (087) identify the county.

What is the largest town in Washington County?

Weiser, with 6,112 residents inside Washington County in 2024.

Which counties border Washington County?

5 county-equivalents border it in the Census 2024 adjacency file: Malheur County, OR; Payette County, ID; Gem County, ID; Baker County, OR; Adams County, ID.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.