Village, Ogle County, Illinois
Radon Testing in Mount Morris, IL
Updated
IEMA has 89 radon test results on record for Mount Morris. 71.9% came back at or above the EPA's action level of 4.0 pCi/L. That is well above the Ogle County rate of 49.7%. A standard test runs $150 to $300. The only way to know about one specific house is to test it.
About 2,726 people live in Mount Morris, a Ogle County village with roughly 1,399 housing units and a median year built of 1953. It sits near Oregon and Rochelle. It's a small Ogle County village west of Rochelle and Oregon.
What IEMA's radon test records show
Look past the median to the tail: 5.6% of Mount Morris 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 Mount Morris is 8.03 pCi/L, against 5.98 for Ogle 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+ | |
|---|---|---|---|---|---|
| Mount Morris | 89 | 8.03 | 71.9% | 28.1% | 5.6% |
| Ogle County | 1,751 | 5.98 | 49.7% | 15.7% | 3.9% |
Source: IEMA radon test records, Illinois Emergency Management Agency.
The ground under Mount Morris
South of Winnebago and Boone Counties, Ogle County follows the Rock River over the same dolomite and limestone bedrock family, with Ordovician rock exposed in places near the river itself. Like its neighbors to the north, the EPA rates Ogle County Radon Zone 1, its highest-potential category.
Housing in Mount Morris
Census Bureau, American Community Survey 2020 to 2024 5-year estimates.
| Homes (housing units) | 1,399 | 22,682 in Ogle County |
| Median year built | 1953 | 1972 countywide |
| Built before 1980 | 92.8% | 71.8% countywide |
| Attached (rowhome, townhouse) | 1.5% | 2.2% countywide |
| Mobile homes | 0% | 2.5% countywide |
| Renter-occupied | 30% | 24.6% countywide |
33.2% of homes in Mount Morris were built before 1940, against 20.1% county-wide. Houses that old usually sit on stone or early block foundations with plenty of joints for soil gas to move through. That does not mean they cannot be tested and fixed, just that a mitigation contractor may need more than one suction point. With 30% of Mount Morris's housing renter-occupied, landlord testing questions come up often. There is no Illinois requirement to test a rental, but plenty of owners do it between tenants when the unit sits empty anyway.
What we do in Mount Morris
Radon testing, Buying or selling a home, and New construction.
Common questions
Is radon a problem in Mount Morris?
Yes. Out of 89 IEMA-recorded tests taken in Mount Morris, 71.9% came in at 4.0 pCi/L or higher, the EPA's action level. That fits Ogle County's overall Zone 1 rating, the agency's highest-potential class.
What is the highest radon reading on record near Mount Morris?
38 pCi/L, out of 89 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.
I rent in Mount Morris. Can I get my unit tested?
Nothing in Illinois law stops a tenant from asking for a radon test, and plenty of landlords in Mount Morris test between leases anyway, since an empty unit is the easiest time to do it.
Need radon testing booked in Mount Morris?
Tell us why you're testing and any deadline you're working against. You get a fixed price and a straight answer back.