San Francisco, CA Radon Mitigation and Testing

Q: What is the average radon level in San Francisco, CA?

Based on 2 user-submitted tests, the average radon level is 3.50 pCi/L.

Q: What EPA Radon Zone is San Francisco in?

San Francisco is in San Francisco County, EPA Zone 2.

Q: How much does radon mitigation cost in San Francisco?

Radon mitigation typically costs between $800 and $2,000. Most standard systems fall in the $1,000-$1,500 range.

Avg: 3.50 pCi/L

San Francisco County

EPA Zone 2

2 user tests

San Francisco is located in San Francisco County, California. With 2 user-submitted readings averaging 3.50 pCi/L, levels are currently below the EPA's recommended action level of 4.0 pCi/L. However, we recommend all homes be tested regardless of your neighbor's results.

3.50

pCi/L average

Below EPA Action Level

Based on 2 user-submitted radon tests for homes in San Francisco, CA. The EPA recommends taking action at or above 4.0 pCi/L.

4.0 EPA

10+

San Francisco, CA Radon Mitigation

Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.

San Francisco, CA Radon Testing

Finding qualified radon testing professionals is the first step toward protecting your home.

San Francisco, California Radon Levels

User-submitted radon test readings from homes in the San Francisco area.

Radon Level	City	Home Age	Foundation	Submitted
5 pCi/L	San Francisco, CA	0-20 Years	No Basement/All Slab	Nov 2024
2 pCi/L	San Francisco, CA	21-50 Years	—	May 2017

Have a radon test result for San Francisco? Submit your reading to help other homeowners.

San Francisco Radon Facts

Key details about the radon risk profile for San Francisco and the 94101 zip code area.

EPA Radon Zone

Zone 2 — Moderate Risk

County

San Francisco County, CA

Zip Code

94101

Predicted Screening Level

2–4 pCi/L (Zone 2)

Avg. User Submitted Level

3.50 pCi/L

User Tests Submitted

San Francisco and the 94101 zip code are located in San Francisco County, which has an EPA assigned Radon Zone of 2. A radon zone of 2 predicts an average indoor radon screening level between 2 and 4 pCi/L. The EPA recommends testing every home regardless of zone classification.

Radon FAQ for San Francisco, CA

What is the average radon level in San Francisco, CA?

Based on 2 user-submitted tests, the average radon level in San Francisco is 3.50 pCi/L. This is below the EPA's recommended action level of 4.0 pCi/L. However, we recommend all homes be tested regardless of your neighbor's results.

What EPA Radon Zone is San Francisco in?

San Francisco and the 94101 zip code are in San Francisco County, which has an EPA assigned Radon Zone of 2. A zone of 2 predicts an average indoor radon screening level between 2 and 4 pCi/L.

How much does radon mitigation cost in San Francisco?

Radon mitigation in San Francisco typically costs between $800 and $2,000. Most homes with standard basements can be mitigated with a sub-slab depressurization system in the $1,000–$1,500 range. Factors that can increase cost include complex foundations, crawl spaces, or very high radon levels.

Should I test for radon if I'm buying a home in San Francisco?

Yes. Radon testing should be part of every home purchase. A short-term radon test is typically included as part of the home inspection process and costs $150–$250. If elevated levels are found, you can negotiate mitigation as part of the sale.

Most Active Radon Markets in California

Cities with the most user-submitted radon test data in the state.

City	Avg User Radon Level	Submissions
Los Angeles	7.83 pCi/L	6
Mammoth Lakes	10.80 pCi/L	5
San Jose	4.20 pCi/L	5
Rancho Palos Verdes	8.00 pCi/L	4
Woodland Hills	7.67 pCi/L	3
South Lake Tahoe	6.33 pCi/L	3
Palos Verdes Peninsula	6.00 pCi/L	3
Bishop	5.67 pCi/L	3
Sacramento	4.33 pCi/L	3
Oakland	3.33 pCi/L	3
Fresno	10.00 pCi/L	2
Davis	8.00 pCi/L	2
Palo Alto	6.50 pCi/L	2
Studio City	6.50 pCi/L	2
Menlo Park	5.00 pCi/L	2
Truckee	5.00 pCi/L	2
Walnut Creek	4.00 pCi/L	2
San Diego	3.50 pCi/L	2
San Francisco	3.50 pCi/L	2
Belmont	20.00 pCi/L	1