Village, Boone County, Illinois
Radon Testing in Caledonia, IL
Updated
IEMA has 149 radon test results on record for Caledonia. 47.7% came back at or above the EPA's action level of 4.0 pCi/L. That is close to the Boone County rate of 49.8%. A standard test runs $150 to $300. The only way to know about one specific house is to test it.
Caledonia is a small Boone County village, established in 1854 and incorporated in 1996, sitting in Caledonia Township near the Winnebago County line. It has about 226 residents and 124 housing units on just over 1 square mile.
What IEMA's radon test records show
Look past the median to the tail: 1.3% of Caledonia tests were 20 pCi/L or more, five times the action level. The top reading on record is 38 pCi/L. The average result in Caledonia is 4.79 pCi/L, against 5.22 for Boone County overall. IEMA's own dataset covers tests licensed measurement professionals submitted from 2003 through July 2019, keeping only the highest reading on record per address. That means it is not a random sample and not year-by-year, but it is the closest thing to primary local radon data that Illinois publishes.
| Tests | Avg pCi/L | 4+ pCi/L | 10+ | 20+ | |
|---|---|---|---|---|---|
| Caledonia | 149 | 4.79 | 47.7% | 10.1% | 1.3% |
| Boone County | 1,628 | 5.22 | 49.8% | 12.4% | 2.1% |
Source: IEMA radon test records, Illinois Emergency Management Agency.
The ground under Caledonia
East of Winnebago County, Boone County shares the same underlying bedrock: Ordovician and Silurian dolomite and limestone, buried under glacial till left by the last Ice Age. That geology puts Boone County in the EPA's Radon Zone 1 too, the agency's highest-potential classification.
Housing in Caledonia
Caledonia has an estimated population of 226 and 124 housing units across 1 square miles. Density comes out to about 226 people per square mile, more settled than the county's most rural townships. The Census Bureau doesn't separately publish a detailed housing-age or tenure breakdown at this population size, so Boone County's own numbers, on the other Boone County pages on this site, are the closest real context for Caledonia specifically, not a figure unique to it.
Source: U.S. Census Bureau, American Community Survey 2020-2024 5-year estimates (via Census Reporter) and 2024 TIGER/Line county subdivision and place boundaries.
What we do in Caledonia
Radon testing, Buying or selling a home, and New construction.
Common questions
Is radon a problem in Caledonia?
Yes. Out of 149 IEMA-recorded tests taken in Caledonia, 47.7% came in at 4.0 pCi/L or higher, the EPA's action level. That fits Boone County's overall Zone 1 rating, the agency's highest-potential class.
What is the highest radon reading on record near Caledonia?
38 pCi/L, out of 149 IEMA-recorded tests. That is an outlier, not typical, but it shows why testing rather than guessing matters: neighboring houses can differ by a wide margin.
We're closing on a house in Caledonia soon. Is there time to test?
In most cases, yes. Scheduled early in the inspection period, a short-term test (a few days to about a week) has time to come back before you need to decide anything. Details on our <a href="/real-estate-radon-testing">real estate radon testing</a> page.
Nearby
Timberlane, Belvidere (47.9% of tests at 4+ pCi/L), Boone Township.
Need radon testing booked in Caledonia?
Tell us why you're testing and any deadline you're working against. You get a fixed price and a straight answer back.