Jefferson County, Idaho
Jefferson County, Idaho, has 35,297 residents (July 2025 estimate). Its county seat is Rigby. It uses Mountain Time and covers 1,094 sq mi (2,833 km²) of land.
- Resident population, July 2025
- 35,297
- Land area
- 1,094 sq mi (2,833 km²)
- County seat or government
- Rigby
- Time zone
- Mountain TimeUTC-07:00 in January; UTC-06:00 in July
- Median household income
- $86,679 ± $3,818
- Median home value
- $408,400 ± $21,935
- Median rent, with utilities
- $1,138 ± $85
- Homes lived in by their owners
- 83% ± 2.4 points
- County type
- County
- Metro or micro area
- Idaho Falls, ID metro areaOutlying county
- Water area
- 12 sq mi (31.2 km²)
- State
- Idaho
- County code (FIPS)
- 16051
- Coordinates (central point)
- 43.796965, -112.318588
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 Jefferson County
| Time zone | Local time and UTC offset | Next clock change |
|---|---|---|
| Mountain TimeAmerica/Boise | 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
- 8340147,972 people
- 8340229,994 people
- 8344225,609 people
- 834341,816 people
- 834431,364 people
- 834441,261 people
- 834501,207 people
- 834311,045 people
- 83425622 people
- 83435600 people
10 ZIP Code areas overlap Jefferson 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 Jefferson County, largest first
- Jefferson County Joint School District 25128,220 people
- Ririe Joint School District 2523,230 people
- West Jefferson School District 2532,360 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.
- Rigby, Idaho (city)5,404 people
- Ririe, Idaho (city)1,079 people
- Menan, Idaho (city)876 people
- Roberts, Idaho (city)609 people
- Mud Lake, Idaho (city)491 people
- Lewisville, Idaho (city)453 people
- Hamer, Idaho (city)59 people
Bordering areas, nearest first
Distances are straight lines between map points.
- Madison County, Idaho33 mi east
- Clark County, Idaho34 mi north
- Bingham County, Idaho40 mi south
- Butte County, Idaho44 mi west
- Bonneville County, Idaho45 mi southeast
- Fremont County, Idaho51 mi northeast
Before using this answer on a form
Use a precise point for address-level questions. A device accuracy circle can cross a boundary; confirm tax, voting or jury details with the responsible office.
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