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California -- population 10,005,712

Los Angeles County, CA Property Research

Real data from four public sources, not an internal estimate: the EPA's radon zone classification, Census housing-age records, FEMA's natural hazard risk index, and NOAA's recorded storm history for this county. Every figure below links to where it actually comes from.

Hazard Summary

Los Angeles County, CA hazard summary: FEMA National Risk Index rated Very High; EPA radon zone 2 of 3; most frequently recorded hazard is flash flood (89 events, 2015-2024).

Radon Risk

Zone 2 -- moderate potential. EPA predicts an average indoor radon screening level between 2 and 4 pCi/L for this county.

This is a county-wide prediction from geology and soil data, not a measurement of any specific home -- EPA recommends testing every home regardless of zone. See our guide on negotiating radon mitigation after inspection.

Source: EPA Map of Radon Zones

Housing Age

Los Angeles County has 3,624,084 housing units. About 57% were built in 1969 or earlier -- old enough that knob-and-tube wiring, lead-based paint, and galvanized supply lines are all realistic possibilities worth checking for, not just a general inspection line item.

2020 or later
19,884
2010-2019
161,612
2000-2009
204,277
1990-1999
225,956
1980-1989
434,144
1970-1979
503,630
1960-1969
511,143
1950-1959
694,167
1940-1949
348,843
1939 or earlier
520,428

Does knob-and-tube wiring have to be replaced before closing?

Source: U.S. Census Bureau, ACS 5-Year Estimates, Table B25034

Natural Hazard Risk

FEMA rates Los Angeles County's overall natural hazard risk as Very High, relative to the rest of the country.

EarthquakeVery High
Inland FloodingVery High
WildfireVery High
Heat WaveRelatively High
LandslideRelatively High
Source: FEMA National Risk Index

Recorded Storm History (2015-2024)

NOAA recorded 143 storm events in Los Angeles County between 2015 and 2024. This is actual event history, not a risk model -- the counts below are individually logged storms, not a prediction.

Flash Flood
89
Thunderstorm Wind
23
Debris Flow
15
Hail
9
Tornado
5
Funnel Cloud
1
Lightning
1
Source: NOAA National Centers for Environmental Information, Storm Events Database

Guides Relevant to This County's Housing Stock

Does a Standard Home Inspection Check for Asbestos?Can Cast Iron Sewer Pipes Fail a Standard Home Inspection?What Is a Federal Pacific Stab-Lok Panel and Why Inspectors Flag It?Do Federal Pacific (FPE) Panels Affect Insurance Like Zinsco Panels?Will a Zinsco Panel Fail a 4-Point Inspection?Can I buy a house with knob-and-tube wiring?

Get Your Free Property Report

BeforeRegret pulls live seismic hazard data, validates the address, and builds era- and county-specific inspection priorities and seller questions into one report -- with anything not yet independently verified clearly labeled, not guessed at.

Get Your First Report Free

This page reports what these four public agencies have published for Los Angeles County as a whole -- it is not an assessment of any specific address or property, and does not replace a licensed home inspection, radon test, or insurance review for a specific home. Data last checked August 10, 2026.