Los Alamos County, New Mexico
Los Alamos County, New Mexico, has 19,407 residents (July 2025 estimate). Its county seat is Los Alamos. It uses Mountain Time and covers 109 sq mi (283 km²) of land.
- Resident population, July 2025
- 19,407
- Land area
- 109 sq mi (283 km²)
- County seat or government
- Los Alamos
- Time zone
- Mountain TimeUTC-07:00 in January; UTC-06:00 in July
- Median household income
- $147,139 ± $10,556
- Median home value
- $495,800 ± $24,607
- Median rent, with utilities
- $1,375 ± $119
- Homes lived in by their owners
- 74.8% ± 3.2 points
- County type
- County
- Metro or micro area
- Los Alamos, NM micro areaCentral county
- Water area
- 0.08 sq mi (0.21 km²)
- State
- New Mexico
- County code (FIPS)
- 35028
- Coordinates (central point)
- 35.870047, -106.307968
These coordinates mark a central point for the area, not a street address. Income, home value, rent and homes lived in by their owners: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, ± margin at 90% confidence; checked on October 13, 2026.
Time zones in Los Alamos County
| Time zone | Local time and UTC offset | Next clock change |
|---|---|---|
| Mountain TimeAmerica/Denver | UTC-07:00 in January; UTC-06:00 in July. Enable JavaScript for the live clock. | Enable JavaScript for upcoming changes. |
Near a time-zone line, check where you are with the time-zone finder. Your phone’s setting can differ.
ZIP Code areas, largest first
2 ZIP Code areas overlap Los Alamos County. People counts are 2020–2024 estimates for each whole ZIP area. Mailing ZIPs can differ; check an address with USPS ZIP Code Lookup.
Official county information
We don’t have a website for this county yet. The US government’s local-office directory ↗ lists its offices. A geographic lookup cannot determine eligibility, tax liability or a court obligation.
School districts in Los Alamos County, largest first
- Los Alamos Public Schools19,435 people
Districts with land in the county; a district can cross county lines. People counts are American Community Survey 2020–2024 5-year estimates. A district boundary doesn’t decide which school a student attends.
Cities, towns and communities, largest first
These areas overlap the mapped boundary; an overlap does not mean that every address belongs to both.
- Los Alamos, New Mexico (CDP)13,317 people
- White Rock, New Mexico (CDP)5,716 people
Bordering areas, nearest first
Distances are straight lines between map points.
- Santa Fe County, New Mexico31 mi southeast
- Sandoval County, New Mexico35 mi west
- Rio Arriba County, New Mexico49 mi northwest
Before using this answer on a form
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