City profile
Waterloo, IL
Monroe County · Population 11,129
Waterloo is a town in Monroe County, IL with about 11,129 residents and a typical home value near $250,000. It is 20 miles from St. Louis, MO, which shapes its climate, healthcare access and amenities.
Climate
Climate type
Four seasons
Winter avg
34°F
Summer avg
80°F
Sunny days / yr
205
Home prices & cost of living
Median home price
$249,500
Typical monthly housing
$1,786
Cost of living (100 = U.S.)
96
Taxes
- Property tax
- 2.07%
- State income tax (top)
- 4.95%
- Social Security
- Not taxed
- Pensions
- Not taxed
- Sales tax (state + avg. local)
- 8.86%
FEMA natural hazard risk
Very Low · county score 42/100
Top hazards: Heat wave, Earthquake, Landslide
Nearest major airport
31 mi to St. Louis Lambert International Airport (STL)
Political lean (2024 county vote)
Leans Republican · 31% Democratic / 67% Republican
Community
Population
11,129
Black population
1.0%
County
Monroe County
Detailed crime figures are available for our 201 hand-researched cities.
2025–2026 trends
2026 market trends
- ▸More retirees are leaving IL than arriving, mostly over cost
- ▸Home prices are still rising in 2026 — good for long-term value, less room to negotiate
- ▸Climate/cost risks to check: severe storms
Highlights
- About 11,129 residents
- Typical home value about $250,000
- 20 miles from St. Louis, MO
Trade-offs
- Smaller community with fewer local amenities
- Scores for this place are estimated from Census data and the nearest major city
Figures are estimates from public sources (see How we match). Verify before making decisions.