Resource · Cincinnati, OH
Greater Cincinnati Radon Zones, by ZIP Code and County
Every county in Greater Cincinnati that touches our service area is classified by the EPA as Radon Zone 1, the highest-risk tier. That means the predicted average indoor screening level for a typical home is at or above 4.0 pCi/L, the EPA action level. Roughly 1 in 3 homes tested in Hamilton County exceeds that threshold per Ohio Department of Health data.
The table below maps the ZIP codes inside our service area to their county and EPA zone, with the typical pCi/L range observed in regional testing programs and the recommended next step. ZIP-level data is summary only: actual readings vary house-to-house based on foundation type, age, and sealing. Test before you mitigate.
| ZIP code | County / Zone | Typical screening range |
|---|---|---|
| 45202 | Hamilton, OH / Zone 1 | Downtown Cincinnati. 2.0-6.0 pCi/L typical for residential conversions; commercial slabs often lower. |
| 45208 | Hamilton, OH / Zone 1 | Hyde Park / Mt. Lookout. 4.0-9.0 pCi/L common in pre-1950 stone-basement housing. |
| 45209 | Hamilton, OH / Zone 1 | Norwood. 4.0-12.0 pCi/L common; some of the highest pre-mitigation readings in the county. |
| 45226 | Hamilton, OH / Zone 1 | Mt. Lookout / Mt. Washington. 3.0-7.0 pCi/L typical. |
| 45227 | Hamilton, OH / Zone 1 | Madeira. 2.0-5.0 pCi/L typical; newer stock often has passive stacks. |
| 45236 | Hamilton, OH / Zone 1 | Kenwood / Sycamore Township. 2.0-5.0 pCi/L typical. |
| 45040 | Warren, OH / Zone 1 | Mason. 1.5-4.0 pCi/L typical; passive stacks common in post-1995 builds. |
| 45069 | Butler, OH / Zone 1 | West Chester. 1.5-4.0 pCi/L typical; mostly newer construction. |
| 45140 | Hamilton/Clermont, OH / Zone 1 | Loveland. 2.0-5.0 pCi/L typical; higher near the Little Miami River corridor. |
| 45150 | Clermont, OH / Zone 1 | Milford. 4.0-9.0 pCi/L common in older limestone-basement stock. |
| 45242 | Hamilton, OH / Zone 1 | Blue Ash / Montgomery. 2.0-5.0 pCi/L typical. |
| 45243 | Hamilton, OH / Zone 1 | Indian Hill. 2.0-6.0 pCi/L typical; multi-zone mitigation common on larger custom builds. |
| 45244 | Hamilton/Clermont, OH / Zone 1 | Anderson Township. 3.0-6.0 pCi/L typical; hillside lots may need drainage attention. |
| 45249 | Hamilton, OH / Zone 1 | Loveland / Symmes. 2.0-4.0 pCi/L typical. |
| 41076 | Campbell, KY / Zone 1 | Cold Spring (where LeadTimber LLC keeps its mailing address). KY DPH classifies this as Zone 1; readings track Hamilton County levels. |
If your ZIP is not listed, your county is still likely Zone 1 across Greater Cincinnati. The action item is the same regardless: order a 48-hour test from a NRPP- or NRSB-credentialed professional, or pick up an EPA-approved short-term test kit ($15-$30) from the Ohio Department of Health or a hardware store. If your reading is above 4.0 pCi/L, mitigate. If it falls between 2.0 and 4.0 pCi/L, the EPA recommends "considering" mitigation, especially if children or chronic-respiratory residents live in the home.
Free phone consultations connect you with a partner-network NRPP-credentialed mitigator who can scope your specific home in 10 minutes and quote a fixed price on the same call.
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