Custer County, Idaho Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 40th-largest in Idaho
The population of Custer County, Idaho is 4,411 as of the 2023 American Community Survey, making it the 40th-largest county in Idaho. The median household income is $56,957, the median home value is $295,600, and the median age is 59.5.
The population of Custer County has grown 5.5% since 2010 (4,357 → 4,597), a +0.38% annualized rate.
4,411
Population
+0.38%
Annual growth
1
People / sq mi
$56,957
Median Income
$295,600
Median Home Value
Custer County covers 4,922 sq mi of land at 0.9 people per square mile.
About Custer County, ID
Custer County skews on age — the median resident is 59.5, older than the national median. With 4,411 residents, Custer County is a county in Idaho. It ranks #40 among counties in Idaho by population.
Median household income is $56,957, below the US median of $78,538. The poverty rate, 4.9%, is on the lower side for US counties and below the national 12.4%. The median home value is $295,600, with typical rent around $744.
Roughly 25.2% of adults have a bachelor’s, below the national 35.0%. Remote work is widespread — 25.0% of workers stay home, above the national 14.0%, and the average commute runs about 17 minutes each way.
The age structure shapes everything downstream in Custer County — from housing demand to the mix of working-age earners reflected in the income figures above.
Custer County Population History (2010-2024)
The county of Custer County had a population of 4,357 in 2010 and 4,597 in 2024, a 5.5% growth over 14 years. The peak was 4,597 in 2024. Average annual growth rate: 0.40%.
4,597
Population (2024)
4,357
Population (2010)
4,597
Peak (2024)
0.40%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 4,357 |
| 2011 | 4,325 |
| 2012 | 4,327 |
| 2013 | 4,226 |
| 2014 | 4,134 |
| 2015 | 4,061 |
| 2016 | 4,089 |
| 2017 | 4,138 |
| 2018 | 4,216 |
| 2019 | 4,273 |
| 2020 | 4,269 |
| 2021 | 4,444 |
| 2022 | 4,503 |
| 2023 | 4,531 |
| 2024 | 4,597 |
Race & Ethnicity
| White | 89.9% |
| Black or African American | 0.3% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 3.4% |
| Two or More Races | 0.0% |
Age & Sex
59.5
Median Age
47.9%
Female
52.1%
Male
36.2%
Age 65+
Age Distribution
Children (under 15): 9.2% · Seniors (65+): 36.2%
Income & Poverty
| Median household income | $56,957$-17,679 vs state |
| Mean household income | $65,974 |
| Per-capita income | $29,993 |
| Poverty rate | 4.9%-2.1% vs state |
| Unemployment rate | 1.0% |
| Employment-to-population | 46.9% |
Top Industries by Employment
The largest employment sector in Custer County is professional & business services, accounting for 22.4% of workers.
How residents commute
0.9%
Drive alone
4.2%
Carpool
56.6%
Public transit
25.0%
Work from home
16.8 min
Avg commute
Housing
$295,600$-80,400 vs state
Median home value
$744
Median rent
77.7%
Homeownership rate
3,164
Total housing units
61.1%
Occupied
38.9%
Vacant
22.3%
Renter-occupied
Social & access
85.9%
With health insurance
90.5%
With broadband internet
54.7%
Foreign-born
13.5%
Veterans (18+)
27.1%
With a disability
98.2%
Speak language other than English at home
Education
93.6%
High School+
25.2%
Bachelor's+
Largest cities in Idaho
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County rankings
Frequently Asked Questions
Custer County, Idaho has a population of 4,411 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 40th-largest county in Idaho. Population density is 1 people per square mile.
The population of Custer County has grown 5.5% since 2010 (4,357 → 4,597), a +0.38% annualized rate.
The median household income in Custer County, Idaho is $56,957, with mean (average) household income of $65,974 and per-capita income of $29,993. 4.9% of residents live below the federal poverty level.
In Custer County, the largest racial and ethnic groups are White (89.9%), Hispanic or Latino (3.4%), Black or African American (0.3%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Custer County, Idaho is 59.5 years. Residents are 47.9% female and 52.1% male.
The median home value in Custer County is $295,600 and median monthly rent is $744. 77.7% of occupied housing units are owner-occupied. The county has 3,164 total housing units, 38.9% of which are vacant.
The largest employment sector in Custer County, Idaho is professional, scientific, and management services, employing 22.4% of workers. The unemployment rate is 1.0%.
Boise City is among the largest cities associated with Custer County, Idaho, with a population of 235,701.
Custer County, ID Climate
Custer County, ID has an average annual temperature of 4.7°C (40°F) and receives about 284 mm of precipitation per year. The warmest month is July and the coldest is January. Figures are 1970–2000 climate normals.
4.7°C
Avg Temp
284
Precip (mm/yr)
Jul
Hottest Month
Jan
Coldest Month
| Month | Avg (°C/°F) | Precip |
|---|---|---|
| January | -7° / 19° | 26 mm |
| February | -4° / 24° | 22 mm |
| March | -1° / 31° | 23 mm |
| April | 4° / 38° | 17 mm |
| May | 8° / 47° | 31 mm |
| June | 13° / 55° | 32 mm |
| July | 17° / 63° | 22 mm |
| August | 17° / 62° | 21 mm |
| September | 12° / 54° | 22 mm |
| October | 6° / 43° | 16 mm |
| November | -2° / 29° | 23 mm |
| December | -7° / 20° | 29 mm |
1970–2000 normals from WorldClim 2.1 (~9 km grid). Precipitation can be less precise near mountains or coastlines, where rainfall varies sharply over short distances.
Best time to visit Custer County, ID
The most comfortable months to visit Custer County, ID are typically July, August and June, when temperatures are mildest and rainfall is relatively low. The hottest month is July (around 28°C high). The coldest is January (near -13°C low). June is usually the wettest month.
Where to stay near Custer County
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Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.