Moderate Risk

ZIP Code 93943

Monterey County, California

Zone 2EPA Classification
2-4Predicted pCi/L
40.4%Above action level
0246810
2pCi/L
Consider mitigation

What This Means

Monterey County, California is in EPA Radon Zone 2, indicating moderate radon potential. Predicted average indoor radon levels are between 2.0 and 4.0 pCi/L. While below the EPA's 4.0 pCi/L action level on average, many individual homes in Zone 2 areas can still have elevated radon. The EPA recommends testing all homes regardless of zone.

What You Should Do

1
Test your home. Use a short-term or long-term radon test kit. Even in moderate-risk areas, many individual homes exceed the EPA action level.
2
If your result is 2.0–4.0 pCi/L, consider mitigation — especially if you have a basement, plan to stay long-term, or have smokers in the household.
3
If your result is 4.0 pCi/L or above, install a mitigation system. Re-test every 2 years going forward.

EPA Zone Details

ZIP Code93943
CountyMonterey
City—
StateCalifornia (CA)
EPA Radon ZoneZone 2 — Moderate
Predicted Indoor Radon2-4 pCi/L

Source: EPA Map of Radon Zones

CDC Testing Data

Homes Tested52
Above 4.0 pCi/L21
% Exceeding Action Level40.4%

Source: CDC Environmental Health Tracking Network

Radon & Your Basement in Monterey County

Monterey County is in EPA Zone 2. Basements in this area may have radon levels that exceed the EPA action level, even though the county average is moderate. Many homes in Zone 2 areas still require mitigation.

Radon concentrations are typically highest in the lowest level of a home. However, radon does not stay confined to the basement — it migrates to upper floors through stairways, HVAC ducts, and gaps in flooring. Even if your basement is unfinished or rarely used, elevated radon there can affect the air quality on your main living floors. Always test on the lowest livable level.

Monterey County Radon Map

Counties colored by EPA radon zone. Red = Zone 1 (high), Orange = Zone 2 (moderate), Green = Zone 3 (low).

Check Another ZIP Code

Nearby ZIP Codes

93940 Del Rey Oaks, CA Moderate 93941 Monterey, CA Moderate 93942 Monterey, CA Moderate 93944 Monterey, CA Moderate

Frequently Asked Questions

What is the radon risk level for ZIP code 93943?

ZIP code 93943 is in Monterey County, California, which is classified as EPA Radon Zone 2 (moderate risk). The predicted average indoor radon level is 2-4 pCi/L.

Should I test for radon in 93943?

Yes. The EPA recommends testing all homes for radon regardless of zone. As a moderate-risk area, many homes in 93943 may still have elevated levels.

What county is ZIP code 93943 in?

ZIP code 93943 is in Monterey County, California (CA).

Is it safe to live in ZIP code 93943?

ZIP code 93943 is in a moderate-risk area. Many homes in this zone have safe radon levels, but some exceed the EPA action level. Testing your specific home is the only way to know for certain.

Does radon in the basement affect upper floors in Monterey County?

Yes. Radon enters through the foundation and can migrate to upper floors through stairways, HVAC systems, and structural gaps. While concentrations are typically highest at the lowest level, upper floors in Monterey County homes can still have measurable radon. Always test on the lowest livable floor.

How much does radon mitigation cost in California?

In California, radon mitigation systems typically cost between $800 and $2,500 depending on home size, foundation type, and local labor rates. The most common system (sub-slab depressurization) averages $1,000-$1,500. The fan lasts 10-15 years and costs $150-$300 to replace. Some states offer financial assistance programs for radon mitigation.