Locations and reports
Radon in Longmont, Colorado
Longmont lies in 2 counties, in EPA Zone 1. Homes with elevated levels occur in all three zones, so the only way to know your home's level is to test it.
Data checked By Radon411Methodology
- Predicted
- Zone 1Highest predicted potential
- Measured
- By countyEach county's own CDC figures are set side by side below.
- Your home
- Test to knowNo area figure here is a reading of your home.
The data
Longmont, What is published
What is published for Longmont
Radon data is published by county, not by city
Radon data is published by county, not by city. EPA assigns radon zones to counties, and CDC publishes radon test figures by county. Neither publishes a figure for Longmont, so every radon figure on this page belongs to a county and is labelled with it. Only a test tells you about one home.
Each county has its own CDC test figures, shown below side by side. About 100,109 people live in Longmont.
Longmont, Counties
Longmont's counties, side by side
MeasuredEach county's own EPA zone and its own published CDC figures for 2023, the newest period any of them has. A county without a figure for that period is shown without one, never with a figure from another year.
- Boulder County
- EPA zone
- Zone 1: Highest predicted potential
- At or above 4 pCi/L
- 34.2%
- Median result
- 2.5 pCi/L
- Tests reported
- 1,963 tests
- Annual years on file
- 10
- Weld County
- EPA zone
- Zone 1: Highest predicted potential
- At or above 4 pCi/L
- 46.0%
- Median result
- 3.5 pCi/L
- Tests reported
- 663 tests
- Annual years on file
- 10
| County | EPA zone | Reported tests at or above 4 pCi/L | Median reported result | Tests reported | Annual years on file |
|---|---|---|---|---|---|
| Boulder County | Zone 1: Highest predicted potential | 34.2% | 2.5 pCi/L | 1,963 tests | 10 |
| Weld County | Zone 1: Highest predicted potential | 46.0% | 3.5 pCi/L | 663 tests | 10 |
The median reported pre-mitigation result for 2023 was 2.5 pCi/L in Boulder County and 3.5 pCi/L in Weld County.
CDC counts radon tests that were reported to it, not homes, and figures from few tests can swing widely from year to year. Each county’s report has its full history.
Predicted: EPA Map of Radon Zones, by county. Measured: CDC tracking data, by county, 2023.
Radon Action Brief
National Radon Action MonthPre-sale
The radon brief for Longmont, in one dated file.
- Your area's radon record, explained. EPA's zone and any CDC tests.
- Your plan to test this week. Which test, where it goes, how long.
- Fix costs and pros near you. Costs, EPA's checklist, listed pros.
Save 64%Sale price: $8.99Price after the sale: $25Ends Jan 31Then $25Sale ends January 31, then $25
Local help
Longmont, Local resources
Local resources for Longmont
Who to ask in Colorado: its radon program, test kits and professionals.
- Colorado's radon programColorado Department of Public Health and EnvironmentColorado’s radon program answers questions about testing, mitigation and the rules where you live.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Order a discounted radon test kit
- Compare kits
- Professionals in ColoradoRadon testers and mitigators in Colorado, each with how its listing was checked.
What Colorado's program says
- Licensing of radon professionals
Listed contractors are certified by the National Radon Proficiency Program or the National Radon Safety Board, and must be licensed by the Colorado Department of Regulatory Agencies.
- Disclosure when a home is sold or rented
As of August 7, 2023, landlords in Colorado are required to disclose radon information when a tenant signs a lease agreement.
What it means
Longmont, Questions
Questions about radon in Longmont
What radon zone is Longmont in?
EPA's Map of Radon Zones classifies counties, not cities. Boulder County and Weld County are in Zone 1 (highest predicted potential). A zone is a prediction for a whole county and never tells you the level in one home.
How many radon tests come back high in Longmont's counties?
For 2023, the share of radon tests reported to CDC that were at or above 4 pCi/L was 34.2% in Boulder County (1,963 tests) and 46.0% in Weld County (663 tests). Each is that county's own figure, counting tests reported to CDC, not homes. Radon411 does not average or combine them into a figure for the city.
Should I test my home in Longmont?
Yes. Testing is the only way to know the radon level in a specific building. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. How to test a home.
The answers use the published figures of Boulder County and Weld County, the counties Longmont lies in.
Explore
Longmont, Next steps
What to do next
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