Seneca is a village in LaSalle and Grundy counties in the U.S. state of Illinois. The population was 2,353 at the 2020 census, down from 2,371 at the 2010 census. The LaSalle County portion of Seneca is part of the Ottawa, IL Micropolitan Statistical Area, while the small portion that lies in Grundy County is part of the Chicago metropolitan area.

From Wikipedia, licensed CC BY-SA 4.0 · facts via Wikidata (CC0)

How Seneca ranks

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#83Highest income in IL #71Best schools in IL #197Lowest obesity in IL All IL rankings →

Town numbers

ZIP code61360

Area codeSign in to add

Living in Seneca

Housing in Seneca

$258K▲ 5.2% in a year Typical home value · Zillow

The typical Seneca home is worth about $258,000, up 5.2% in a year, 13% below the Illinois typical home.

Only 3 sales in May 2026, too few for a market read. The typical value is the steadier guide.

Zillow Home Value Index · Redfin Data CenterHousing market →

Safety in Seneca

—

Not graded

A grade needs all of the FBI's latest years (2023–2025). Seneca's police department reported only 2025, so we don't grade it yet. The figures below are still real.

Violent crime per 1,000

Seneca 2.2

Illinois 2.6

U.S. 3.3

Property crime per 1,000

Seneca 8.3

Illinois 15.6

U.S. 15.5

FBI crime data, 2025 · crimes reported to policeCrime & safety →

Work & commute in Seneca

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Most working residents leave Seneca for work: only 5% work in town. The top destinations are Ottawa (11%), Morris (6%) and Marseilles (5%). Half commute less than 25 miles.

Ottawa

11%

Morris

Marseilles

Chicago

5%Work in townlive and work in Seneca 25 miWhere do people commute?the commute map 569Jobs based herea commuter town

Census LEHD 2023 · ACSWork & commute in Seneca →

Health in Seneca

B⁻

Health Grade B−

Healthier than 51% of U.S. towns on seven CDC estimates.

Compared with Illinois

1better than IL·5worse

of 32 measures CDC estimates. The other 26 are too close to call.

Conditions 2▼ 10 close Habits 1▼ 3 close Care 1▲ 1▼ 5 close Mind 1▼ 4 close Everyday needs all close

BetterToo close to callWorse

What stands out

7.7%Fewer uninsured adultsIL 9.9% · better 15.8%More smokersIL 12.1% · worse

Care nearby

Morris Hospital & Healthcare CentersMorris · 10.7 mi · ER

Aunt Martha's Health Center Joliet JeffersonJoliet · 29.1 mi · sliding-scale fees

Primary careShortage · county-wide

DentalShortage · county-wide

Mental healthShortage · county-wide

CDC PLACES 2025 · modeled estimates for adults · CDC's estimate for Seneca · CMS · HRSAHealth in Seneca →

Natural hazards in Seneca

High

Expected storm and flood damage is higher than in 73% of U.S. communities.

🌊 Inland flooding🥶 Cold waves🌪️ Tornadoes

21Does Seneca flood?paid flood claims since 1979 4Disasters that paid out herefederal disasters sent FEMA money to Seneca MapSeneca vs. its neighborsnearby towns shaded by rating

FEMA National Risk Index December 2025 · OpenFEMANatural hazards in Seneca →

Climate in Seneca

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Seneca has chilly winters and warm summers. A typical July afternoon reaches 85°, a January night drops to 16°, and about 25 inches of snow falls in a normal winter.

35° / 19°Winter

61° / 39°Spring

83° / 62°Summer

64° / 42°Fall