Lewis County, Idaho Demographics
Population trends, housing costs, income, commuting, and health, all on one page.
Lewis County, ID Population Density Map and Area Scores
Area Score
Health, income and education, each graded from F to A+. Explore interactive maps for deeper analysis.
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C
Health Below averageAmong the 5 least healthy counties in Idaho
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D
Income Well below averageAmong the 5 least wealthy counties in Idaho
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D
Education Well below average
Source: Map AI Methodology
Population: density and quick facts
| Metric | Lewis County | Idaho Avg | U.S. Average |
|---|---|---|---|
| Population | 3,684 | 1,929,983 | 337,468,954 |
| Population density (per sq mi) | 7.7 | 23.1 | 86.4 |
| Population growth (%/yr) | -0.46% | 2.12% | 0.59% |
| Median age | 47.9 | 38.7 | 37.3 |
| Households | 1,574 | 712,816 | 130,235,071 |
Population in Lewis County grew by 1.1% from 2009 to 2024, reaching 3,684 in 2024.
Population Growth 2009–2024
Race & Ethnicity
Age & Sex
The largest generation in Lewis County is Boomers, aged 61–79, at 27.1% of residents. That is 11.1 points above Idaho as a whole.
- Gen Z 13–28 586 15.9% -6.9 pts
- Millennials 29–44 564 15.3% -5.4 pts
- Gen X 45–60 762 20.7% +1.5 pts
- Boomers 61–79 999 27.1% +11.1 pts
Residents by birth cohort, from the 2025 age distribution. The right-hand figure is how far each cohort's share sits above or below Idaho, in percentage points. Children younger than Gen Z and the generations before the Boomers are counted in the population but not shown here, so these shares do not add up to 100%.
Male and female share
Women are 50.4% of the people living in Lewis County and men 49.6%.
- Women 50.4% Idaho 49.6%
- Men 49.6% Idaho 50.4%
How many residents match a customer profile?
Residents matching this profile
100% of everyone living in Lewis County
Pick an age range and a women/men split and the figure above answers with how many residents that profile reaches.
Economy
Lewis County has a the economy index of D, which means it is barely prosperous.
| Metric | Lewis County | Idaho Avg | U.S. Average |
|---|---|---|---|
| Median household income | $52,248 | $78,141 | $80,455 |
| Income growth (%/yr) | 4.19% | 5.97% | 4.80% |
| Unemployment rate | 2.4% | 3.7% | 5.2% |
The median household income in Lewis County is about 33% lower than in Idaho.
Housing
| Metric | Lewis County | Idaho Avg | U.S. Average |
|---|---|---|---|
| Median home price | $334,614 | $394,140 | $248,835 |
| Median rent | $736 | $1,236 | $1,407 |
| Homeownership rate | 76.4% | 72.3% | 65.2% |
The median home price in Lewis County is about 37.9 years' worth of rent — buying at the median price costs roughly as much as paying the median rent of $736 per month for that long.
Commute Time & Mobility
Commuters in Lewis County spend about 33 minutes on the road round trip each working day. Over a typical 250-day work year, that adds up to roughly 137 hours, about 5.7 full days, spent commuting.
| Metric | Lewis County | Idaho Avg | U.S. Average |
|---|---|---|---|
| One-way commute (min) | 16.5 | 18.0 | 22.4 |
| Round-trip commute (min) | 32.9 | 35.9 | 44.8 |
| Yearly time spent (hours) | 137 | 150 | 187 |
| Estimated yearly cost | $4,250 | $4,641 | $5,790 |
| Work from home | 12.6% | 13.3% | 15.0% |
| Highway traffic (vehicles/day) | 1,282 | 4,714 | 8,813 |
| Local road traffic (vehicles/day) | 123 | 865 | 1,355 |
Fastest commutes among counties in
Idaho:
Custer County (8.9 min), Lemhi County (11.6 min), Madison County (12.0 min).
Slowest:
Camas County (49.5 min), Boise County (38.0 min), Lincoln County (32.0 min).
The average commute time in Lewis County is 16 minutes, shorter than the 18 minutes in Idaho.
Estimated yearly cost applies a single national wage rule of thumb (U.S. Bureau of Labor Statistics average hourly earnings), not a measurement of wages in this area. Traffic volume figures come from proprietary Ticon and TrafficZoom data.
Education & Households
Lewis County has a education index of D, which means it is barely educated.
| Metric | Lewis County | Idaho Avg | U.S. Average |
|---|---|---|---|
| Bachelor's degree or higher | 17.7% | 27.1% | 31.6% |
| Average household size | 2.28 | 2.64 | 2.53 |
Highest education index among counties in
Idaho:
Latah County (0.4), Teton County (0.3), Ada County (0.3).
Lowest:
Clark County (0.1), Owyhee County (0.2), Lincoln County (0.2).
Health
Lewis County has a health index of C, which means it is somewhat healthy.
| Metric | Lewis County | Idaho Avg | U.S. Average |
|---|---|---|---|
| Life expectancy (years) | 81.8 | 79.5 | 78.3 |
| Self-rated poor health | 18.9% | 15.6% | 16.3% |
| Smokers | 19.6% | 17.6% | 19.0% |
Highest health index among counties in
Idaho:
Madison County (0.8), Latah County (0.8), Ada County (0.8).
Lowest:
Shoshone County (0.8), Washington County (0.8), Lincoln County (0.8).
Lewis County, ID Compared With Nearby Counties
Lewis County, ID is the smallest of the 4 counties compared here, 3,684 residents against a local median of 41,044. Lewis County, ID's median household income, at $52,248, runs 27% below the $72,066 typical of the counties around it. That is the weaker end of the local range on this measure.
Commute tells the same story from another angle: 16.5 min against a local median of 13.5 min, 22% above it. Every measure here with a clear better direction points the same way, and it is the wrong way: Lewis County, ID reads weaker than its neighbours on all of them. The counties themselves sit within $6,905 of each other on median household income, a tighter band than the gap between any of them and Lewis County, ID, which makes it a genuine outlier here rather than one end of a wide local spread. Lewis County, ID has the 4th highest median household income of the 4 areas compared here.
| Area | Population | Median household income | Median home price | Commute |
|---|---|---|---|---|
| Lewis County, ID | 3,684 | $52,248 #4/4 | $334,614 #1/4 | 16.5 min #4/4 |
| Nez Perce County, ID | 42,646 | $72,066 | $332,853 | 13.5 min |
| Latah County, ID | 41,044 | $65,983 | $307,459 | 15.6 min |
| Asotin County, WA | 22,455 | $72,889 | $307,123 | 13.2 min |
Frequently Asked Questions
Common questions about Lewis County, Idaho.
How many people live in Lewis County, Idaho?
About 3,684 people live in Lewis County, Idaho, in 1,574 households of 2.3 people on average. The median age is 47.9, so residents are older than the U.S. median of 37.3 by about 11 years.
How densely populated is Lewis County, Idaho?
Averaged over its land area, Lewis County, Idaho has 8 people per square mile, a density typical of rural areas. That is about 9% of the U.S. average of 86.
Is Lewis County, Idaho an affordable place to live?
The median home costs 6.4 times the median household income ($334,614 against $52,248), compared with 3.1 times nationally. A ratio of about 3 is traditionally considered affordable. Median rent of $736 a month takes about 17% of the median household's income, below the 30% level at which HUD considers renters cost-burdened.
Is unemployment high in Lewis County, Idaho?
Unemployment in Lewis County, Idaho is only 2.4%, well below the U.S. rate of 5.2%, a sign of a tight labor market where employers compete for workers.
How common is a college degree in Lewis County, Idaho?
17.7% of adults in Lewis County, Idaho hold a bachelor's degree or higher (about 1 in 6), well below the U.S. share of 31.6%.
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