R
RadonVerdict
EPA Zone 1 - High Risk

Northampton County, PA radon levels: test-to-decision path

Fast county answer: If you landed here from a Northampton County radon-level search, start with the short lane: no reading yet, borderline result, or 4.0+ result. Northampton County is a near-miss county from the search data. Keep the path short: first test, retest a borderline result, or price a confirmed 4.0+ result.

Pick My Next Step I Need to Test First
Quick Read

Keep the county path short

These counties already showed search traction. The page now removes the extra step between county evidence and the next action.

County signal

Near-miss search signal: keep the page focused on the next practical decision.

What the number changes

No reading yet means test first. Borderline means retest. 4.0+ means cost or credit planning.

Fastest next move

Pick one route now: test, retest, local cost, or seller-credit math.

Measured Radon Data

Northampton County evidence before the next step

Northampton County, PA has more than the EPA map: PA DEP Radon Division exposes 51,869 reported tests, 9.5 pCi/L county average, and 1845.1 pCi/L high-end signal for 1990-2025.

Source window

1990-2025

County evidence type

High measured burden

County context only; your home test controls the decision.

Primary result

9.5 pCi/L

57th percentile in-state

4.0+ signal

Not available

n/a in-state

High-end signal

1845.1 pCi/L

93rd percentile in-state

Official evidence dossier

Source record for Northampton County, PA

Pennsylvania values are RadonVerdict county rollups from PA DEP ZIP reports, with basement readings treated as the primary local signal and first-floor readings preserved as a separate floor context.

Open source dataset

Primary public source

Basement and first-floor test data

Measurement window

1990-2025

Retrieved / checked

2026-05-05

County FIPS

42095

Evidence stack

County source

Basement and first-floor test data

Primary source used for the county evidence row.

Federal map

EPA Map of Radon Zones

Zone 1 is context, not a property result.

Housing context

US Census ACS housing context

38.9% built before 1980; 127,724 housing units.

State follow-up

State radon program

Use the state source before hiring or interpreting local rules.

Primary field

9.5 pCi/L

Median field

Not available

4.0+ field

Not available

Sample / volume

51,869 reported tests

Metric shape

PA separates basement and first-floor tests. RadonVerdict treats basement results as the main signal for mitigation planning and keeps first-floor results as context.

Source limitation

PA DEP Radon Division ZIP reports are based on short-term closed-house radon tests submitted by certified radon laboratories and testers from January 1990 through December 2025. PA DEP does not report an average when a ZIP has fewer than 30 tests. RadonVerdict rolls ZIP rows up to primary counties and treats the basement average as the primary local signal while preserving first-floor context.

Property-level limit

Not a property-level diagnosis. The county record explains local evidence; your home's own test result controls the next decision.

County-specific interpretation

Northampton County crosses the action threshold in the official county data.

Northampton County is a test-now case because 9.5 pCi/L average. In-state rank: 57th percentile for average. No reading means get the first number; a 4.0+ home result should move straight to mitigation quotes or seller-credit math.

Real-estate use

Buyer or seller use: ask for a fresh lowest-level test before inspection deadlines, tie any 4.0+ result to a contractor quote, and do not negotiate from the county signal alone.

Northampton County should be treated as a county where a first test is urgent and a 4.0+ result should move directly into mitigation pricing or seller-credit math.

Use This Evidence

Official state path

Open the state radon program

Use state rules and local program contacts before choosing a contractor.

EPA hiring guidance

Find a qualified radon provider

EPA points homeowners to state programs and national proficiency listings.

Certified professional search

Search NRPP-certified pros

Use this after you have a valid result or need professional testing.

High-risk intent answer

Is radon bad in Northampton County?

Northampton County should be treated as a high-priority testing market because 9.5 pCi/L primary measured result, and 1845.1 pCi/L high-end signal in PA DEP Radon Division data. A missing home reading means test now; a 4.0+ result means mitigation pricing or seller-credit math should start.

Home result translator

Enter the result. Pick the deal side. Get the route.

Near-miss search signal: keep the page focused on the next practical decision.

County signal

9.5 pCi/L

At or above 4.0

Not available

Decision side

Foundation clue

No reading yet? Test first. 2.0-3.9 usually means confirm the result. 4.0+ means budget local mitigation or seller-credit math before the conversation starts.
Start with testing steps Open local cost plan

Choose your next step

Start from the exact job, not another generic radon article.

Pick the situation that matches Northampton County, PA. Each route keeps the reading, deal side, or foundation clue attached so the next page answers the search instead of resetting the user.

Failed inspection

I need a repair or seller credit number

Open the local credit path with a 4.0+ buyer scenario already selected.

Open negotiation route

4.0+ pCi/L

I have a high result and need the cost path

Go straight to the county estimate, quote context, and contractor checklist.

Open cost route

2.0-3.9 pCi/L

I need to know if this number is bad

Use the level explanation first, then decide whether to retest, monitor, or price mitigation.

Open level route

No test yet

I need the first valid result

Start with kit placement, timing, closed-house conditions, and result interpretation.

Open testing route

Foundation fast lanes

Basement Slab Crawlspace

Deal fast lanes

Buyer ask Seller response

Already got a bid?

Check quote fairness
Fastest Path

Pick the situation that matches you

You should not need to read the whole guide before clicking one of these. Start with the lane that matches your current stage, then come back for the deeper reference only if you still need it.

Use the Northampton County short path first; the deeper source detail is below if you need it.

No reading yet

I have not tested yet

Do not price mitigation blind. Get the first number, then decide whether you need monitoring, quotes, or nothing at all.

Read the testing guide first Check your state radon program
2.0-3.9 pCi/L

My result is 2.0-3.9

Usually confirm the reading first. If it keeps showing up, use the county evidence and official guidance before deciding whether pricing makes sense.

Confirm the Northampton County borderline result
4.0+ pCi/L

My result is 4.0+

This is the EPA action line. Use the local cost page before calling contractors so you know the likely scope, timing, and budget.

Open the Northampton County local cost path
Buying or selling

I am buying or selling

Turn the reading into a credit or repair number before negotiation starts. This is the faster path than arguing from a generic article.

Turn the Northampton County result into a credit plan

Already tested once and need the cleanest follow-up path?

Review retesting steps

Near-Miss County Playbook

This county gets the short route first.

Search Console already showed enough signal to keep this page focused. The fastest useful answer is whether the visitor needs a first test, a retest, a local cost range, or seller-credit math.

Test Confirm the reading before the money step Use the testing guide if there is no valid short-term, long-term, or continuous monitor result yet. 4.0+ Open the local cost path before calling contractors This keeps the conversation anchored to county evidence, foundation type, and actual result band. Call Use the contractor quote checklist before the call Ask about foundation, suction method, fan, permit, warranty, retest, and exclusions before comparing prices. Quote Check if the contractor quote is fair Screen price, foundation scope, fan, warranty, permit, sealing, and retest before adding an anonymized signal.
Pick My Next Step

County Evidence Snapshot

Northampton County testing context

Source-backed county page

Northampton County should be treated as a testing-priority county because the official source signal backs up the EPA high-zone warning. Official county data shows 9.5 pCi/L as the primary measured signal. Use the EPA map as context, but let the home test decide mitigation or credit planning.

EPA map signal

Zone 1

County-level predicted indoor screening range, not a home-level test result.

Housing base

127,724

82th percentile among 67 PA counties with data.

Older housing share

38.9%

70th percentile in-state; older homes often need clearer test placement decisions.

Median home value

$265,600

Used as context for whether mitigation is a small maintenance item or a negotiation issue.

Measured Radon Data

Pennsylvania DEP Radon Test Data by ZIP Code

1990-2025

Basement average

9.5 pCi/L

At or above 4.0

Not available

Maximum reported

1845.1 pCi/L

Reported tests

51,869

PA DEP floor rollup: basement average 9.5 pCi/L from 46,027 tests; first-floor average 4.7 pCi/L from 5,842 tests.

PA DEP Radon Division ZIP reports are based on short-term closed-house radon tests submitted by certified radon laboratories and testers from January 1990 through December 2025. PA DEP does not report an average when a ZIP has fewer than 30 tests. RadonVerdict rolls ZIP rows up to primary counties and treats the basement average as the primary local signal while preserving first-floor context.

County evidence interpretation

High measured burden

Source-backed context Not a home-specific result

Primary result rank

57th percentile

9.5 pCi/L

4.0+ rank

n/a

Not available at or above 4.0

High-end rank

93rd percentile

1845.1 pCi/L

Test volume rank

84th percentile

51,869 reported tests

How to use this county data

Data source

Basement and first-floor test data

Pennsylvania values are RadonVerdict county rollups from PA DEP ZIP reports, with basement readings treated as the primary local signal and first-floor readings preserved as a separate floor context.

What the numbers show

Basement-focused results

PA separates basement and first-floor tests. RadonVerdict treats basement results as the main signal for mitigation planning and keeps first-floor results as context.

Nearby comparison

Nearby comparison: Closest counties by county average: Union County (9.3 pCi/L) is just lower, and Cumberland County (9.7 pCi/L) is just higher.

How this helps

Use this for basement-level test planning and 4.0+ mitigation or seller-credit decisions in Northampton County.

What the data says

Northampton County, PA is measurement-backed for 1990-2025. The measured average is 9.5 pCi/L. The high-end signal reaches 1845.1 pCi/L.

Northampton County, PA sits at the 57th percentile for measured average, n/a for 4.0+ share, 93rd percentile for high-end readings, and 84th percentile for test volume among 67 measured counties in the state. Closest counties by county average: Union County (9.3 pCi/L) is just lower, and Cumberland County (9.7 pCi/L) is just higher.

What to do with it

Northampton County should be treated as a county where a first test is urgent and a 4.0+ result should move directly into mitigation pricing or seller-credit math.

Retest trigger: a 2.0-3.9 pCi/L home result should be confirmed here because 9.5 pCi/L average keeps the county from being a dismiss-it signal.

Source-backed context from PA DEP Radon Division based on about 51,869 reported tests/properties plus comparable county-level measurement fields.

No reading yet

No reading yet: run a short-term test now, then confirm or price mitigation quickly if the result is elevated.

2.0-3.9 result

2.0-3.9 pCi/L: retest or track longer-term rather than dismissing the result, because the county distribution has meaningful elevated readings.

4.0+ result

4.0+ pCi/L: use the result for mitigation quotes, repair scope, or seller-credit negotiation; the county signal is no longer the deciding input.

Source hierarchy: PA DEP Radon Division is used for this county, with EPA zone and Census housing data kept as supporting context. Pennsylvania values are RadonVerdict county rollups from PA DEP ZIP reports, with basement readings treated as the primary local signal and first-floor readings preserved as a separate floor context.

Direct Answer

Is radon bad in Northampton County?

Northampton County should be treated as a high-priority testing market because 9.5 pCi/L primary measured result, and 1845.1 pCi/L high-end signal in PA DEP Radon Division data. A missing home reading means test now; a 4.0+ result means mitigation pricing or seller-credit math should start.

Evidence Value
Area Northampton County, PA
EPA Zone Zone 1
Primary Recommendation Perform direct radon testing in the lowest livable level

Sources

Your Radon Reading

Enter your home's measured level; the starting value is only a planning example until you have your own result.

5.5 pCi/L
0 2.7 WHO 4.0 EPA 10 20+

Warning: Action Required - EPA Threshold Exceeded

At 5.5 pCi/L, this reading is above the EPA action level. Prompt mitigation planning is recommended after confirmatory testing.

Now
5.5
After
0.3-0.8

Typical mitigation systems reduce radon by 80-99%. See your itemized cost estimate below.

pCi/L

Understanding Radon Levels: Complete Reference

<2.0

Below 2.0 pCi/L - Lower Concern, Keep Testing

Below both the EPA (4.0) and WHO (2.7) action reference levels. This usually means mitigation is not the next immediate step after a confirmed result. The average outdoor radon level is approximately 0.4 pCi/L, and there is no known risk-free indoor level. Periodic testing is still recommended because levels can change over time due to seasonal variations, changes in home ventilation, or foundation settling.

2.0
-4.0

2.0 - 4.0 pCi/L - Elevated, Consider Action

Exceeds the World Health Organization's reference level of 2.7 pCi/L but falls below the US EPA action threshold. The EPA states that homeowners should "consider fixing" homes in this range, especially if the home has a basement used as living space, if children are present, or in connection with a real estate transaction. Practical next step: run a confirmatory long-term test, then compare mitigation quotes if levels remain elevated.

4.0
-8.0

4.0 - 8.0 pCi/L - Action Recommended

Exceeds the EPA action level of 4.0 pCi/L. The EPA and Surgeon General strongly recommend mitigation within a few months. At this level, prioritize confirmatory testing and contractor planning. Standard sub-slab depressurization systems typically reduce indoor levels by 80-99%.

8.0+

Above 8.0 pCi/L - Urgent Action Required

At these levels, the EPA recommends expedited mitigation - ideally within weeks, not months. Occupants should minimize time in lower-level rooms until the system is installed. Use a certified mitigator and request priority scheduling to shorten high-exposure time. Many mitigators offer priority scheduling for homes above 8.0 pCi/L.

Why Radon is a Testing Priority in Northampton County

The EPA map is only the starting layer for Northampton County. Official county data shows 9.5 pCi/L as the primary measured signal. That source-backed signal is why the practical move is testing or retesting before treating the county as low urgency.

This still is not a diagnosis for any single home. Foundation type, lowest-level use, pressure differences, and small geological changes can move one house above or below the county pattern.

If you do not have a reading yet, start with a short-term test in the lowest lived-in level. If the result is 2.0-3.9 pCi/L, confirm it; if it is 4.0+ pCi/L, move into mitigation pricing or seller-credit planning.

Radon & Health: What the Science Says

#2
Leading cause of
lung cancer
21K
US deaths per year
from radon
1 in 15
US homes above
4.0 pCi/L

Radon is a Class A carcinogen - the same classification as asbestos and tobacco smoke. The National Academy of Sciences estimates that radon causes approximately 21,000 lung cancer deaths annually in the United States, making it the leading environmental cause of cancer death.

Unlike smoking, radon exposure is involuntary and often invisible. There is no safe level of radon - risk increases linearly with exposure. The good news: radon mitigation systems are highly effective, typically reducing indoor levels by 80-99% within hours of activation.

Source: US Environmental Protection Agency, "A Citizen's Guide to Radon" (EPA 402/K-12/002). National Academy of Sciences, Biological Effects of Ionizing Radiation (BEIR VI) Report, 1999.

Step 1: Test Your Home

Testing is the only way to know your home's radon level. Zone and county data tell you the regional signal, but your home could be significantly higher or lower than the countywide pattern. Start with a valid test setup before using any cost path.

Testing first
Open the home testing guide
Short-term, long-term, retest, and real-estate setup
Need the official path?

State radon programs and EPA provider guidance are the right reference before hiring or confirming local requirements.

Open the state radon program

Already Know Your Level?

If your test shows 4.0 pCi/L or higher, get an itemized cost estimate specific to Northampton County - including regional labor rates and permit requirements.

Get Mitigation Cost Estimate ->

PA Radon Regulations

!
Seller Disclosure

Pennsylvania requires radon disclosure through the Seller's Property Disclosure Statement. The PA DEP also provides radon-specific guidance for real estate transactions.

yes
Professional Licensing

Pennsylvania requires certification for radon testing and mitigation professionals through the PA DEP.

Official state radon program

How to Test for Radon in Northampton County

1

Buy a Test Kit

Purchase a short-term charcoal test kit online or from a local hardware store. Cost: $15-$30. Place it in the lowest livable level of your home.

2

Wait 2-7 Days

Keep doors and windows closed (except normal entry/exit) during the test period. Avoid running whole-house fans. Mail the kit to the lab provided.

3

Read Your Results

If results are below 4.0 pCi/L, re-test every 2 years or use a monitor for ongoing tracking. If above 4.0, use our cost calculator to see mitigation options.

Related Radon Resources for Northampton County

Action Plan + Cost in Northampton County Use your test result to compare local next steps and budget. Radon Levels: 2.0 vs 4.0 vs 8.0 Understand what the numbers mean before comparing local next steps. PA Radon Levels Hub Compare measured 4.0+ share, high-end readings, and official source coverage. How to Test for Radon Closed-house protocol, kit placement, and retest intervals. Radon Exposure Symptoms Guide Health-risk context for elevated radon environments. Who Pays: Buyer or Seller? Use radon cost context for credits, repairs, and closing negotiation. Local Seller Credit Calculator Turn this county's mitigation range into a repair or credit ask. Measured-risk peer: Indiana County Compare against a same-state county with 7.3 pCi/L primary measured radon result. Measured-risk peer: Chester County Compare against a same-state county with 5.9 pCi/L primary measured radon result. Centre County Levels Compare against a same-state county with 10.0 pCi/L primary measured radon result. Clinton County Levels Compare against a same-state county with 9.0 pCi/L primary measured radon result. Cumberland County Levels Compare against a same-state county with 9.7 pCi/L primary measured radon result.

Explore Other PA Counties

Cumberland Zone 1 - High Risk Huntingdon Zone 1 - High Risk Union Zone 1 - High Risk Franklin Zone 1 - High Risk Centre Zone 1 - High Risk Clinton Zone 1 - High Risk

Official State Resource

Pennsylvania radon program and rules

Use the state program link to verify local radon guidance, disclosure language, and contractor credential expectations before you act on an estimate.

Open official PA resource

Disclosure rule tracked

Pennsylvania requires radon disclosure through the Seller's Property Disclosure Statement. The PA DEP also provides radon-specific guidance for real estate transactions.

State licensing required

Pennsylvania requires certification for radon testing and mitigation professionals through the PA DEP.

Sources & Methodology

Radon zone classifications for Northampton County are sourced from the EPA's Map of Radon Zones, which uses geological surveys, indoor radon measurements, and soil permeability data to assign each county a risk tier.

Disclaimer: Zone data represents county-level screening ranges and cannot predict the radon level in any specific home. Testing is the only reliable method to determine your home's radon concentration. This content is for informational purposes and is not medical advice.

Content review: Source-level retrieval dates

Editorial and Data Transparency

Author
RadonVerdict Data Team (Public Data and Cost Modeling)
Content Review
Source-level dates shown below
Data Retrieved At
2026-02-24

Primary Sources