Los Angeles County, CA climate risk

Los Angeles County in the state and national rankings

National placement for Los Angeles County is #1 of 3,232, with an expected annual loss estimate of about $7.60 billion. Within California, 25.2% of modeled loss belongs here, placing the county #1 of 58. This $7.60 billion estimate is a long-run modeled annual average, not a forecast for a particular year. The next lower national total is about $2.42 billion, in Cook County, IL. Within the state list, Riverside County, CA has the next lower estimate: about $2.27 billion. That puts the estimates about $5.34 billion apart, with 7.5% of state loss in the comparison county.

California county comparisons

Los Angeles County hazard estimates

Earthquake

For earthquakes, the county leads all US counties in modeled expected annual loss, at about $4.57 billion. At 60.1% of the county’s modeled loss, the hazard places #1 of 58 statewide; FEMA assigns a Very High rating; the Very High label covers 7 state counties and 8 nationally for earthquakes.

Riverine Flood

The largest US county estimate for riverine flooding belongs here: about $2.81 billion, ranking #1 of 3,232. Its 36.9% share of total loss comes with a state loss rank of #1 of 58; FEMA assigns a Very High rating; the same rating for riverine flooding covers 9 California counties and 26 across the US.

Wildfire

For wildfires, about $155.2 million in expected annual loss puts the county #3 of 3,144 across the US. This hazard makes up 2.0% of the total; FEMA assigns a Very High rating, and its loss ranks #3 of 58 in California; the Very High label covers 4 state counties and 4 nationally for wildfires.

Heat Wave

FEMA models about $36.8 million in expected annual loss from heat waves, placing the county #25 of 3,202 nationally. In California, this estimate ranks #2 of 58 and represents 0.5% of the county’s modeled loss; FEMA assigns a Relatively High rating; the Relatively High label covers 17 state counties and 98 nationally for heat waves.

Tornado

The national loss rank for tornadoes is #103 of 3,225, based on about $18.3 million in modeled expected annual loss. At 0.2% of the county’s modeled loss, the hazard places #1 of 58 statewide; FEMA assigns a Relatively High rating; for tornadoes, 1 state county and 272 US counties share that label.

Coastal Flood

For coastal flooding, about $5.2 million in expected annual loss puts the county #56 of 588 across the US. Its 0.1% share of total loss comes with a state loss rank of #5 of 21; FEMA assigns a Relatively High rating, matching 60 US counties, including 7 in California, for this hazard.

The loss estimate for earthquakes exceeds riverine flooding by about $1.76 billion, equivalent to 23.1 percentage points of total loss. For riverine flooding, modeled loss is about $2.65 billion above wildfires, leaving 34.9 percentage points between their county shares. About $118.4 million separates wildfires from heat waves in the local estimates, equivalent to 1.6 percentage points of county loss. For heat waves, modeled loss is about $18.5 million above tornadoes, leaving 0.2 percentage points between their county shares. The loss estimate for tornadoes exceeds coastal flooding by about $13.1 million, equivalent to 0.2 percentage points of total loss.

Population and recorded values

FEMA counts 10,005,712 residents in Los Angeles County, across about 4,797 square miles. The recorded building value is about $1,703.72 billion. The recorded agricultural value is about $199.1 million. Per resident, the modeled annual amount is about $760; the California average is about $764. Its 25.3% share of state residents sits alongside 25.2% of of annual loss. The county contains 22.0% of the building value recorded across California. The county holds density position 3 of 58 in California, using FEMA’s recorded population and area. The population-to-area ratio is about 2,086 residents per square mile; statewide it is about 239. At 10,005,712 residents, the county compares with the California county median of about 186,448. In the US totals, the county represents 4.9% of modeled annual loss and 3.0% of recorded residents. For comparison, the US modeled loss average is about $459 per resident; the county figure is about $760. The six hazards described above together make up 99.8% of modeled loss, about $7.59 billion annually. The balance outside those six estimates is about $11.9 million, or 0.2% of total loss. The county’s number 7 hazard by dollar loss is tsunamis: about $3.3 million, with a state rank of #8 of 20. This 0.0% slice of county loss ranks #43 of 119 across US counties. In position 8 locally, lightning has about $2.1 million in modeled annual loss, ranking #1 of 58 statewide. This 0.0% slice of county loss ranks #127 of 3,222 across US counties.

FEMA labels and risk score

Los Angeles County has a FEMA risk index score of about 100.0, ranking #1 of 3,144 nationally. The risk index rating is Very High, a label shared by 9 of 58 California counties. Among 58 California counties, 7 receive the same Very High label for expected annual loss. For social vulnerability, FEMA assigns Relatively Moderate; 14 counties in California have that label. FEMA labels community resilience as Very Low, matching 12 county records across California. Its risk score ranks #1 of 58 within California, while its loss total ranks #1 of 58. The Relatively Moderate vulnerability and Very Low resilience pairing appears in 1 California counties. The group represents 25.2% of statewide loss; this county supplies 100.0% of the group’s modeled amount. On the state risk-score list, Riverside County, CA sits immediately below, scoring about 99.9 and ranking #2 of 58. Its share of statewide modeled loss is 7.5%; FEMA’s risk index label there is Very High. Across the US, this social vulnerability category, Relatively Moderate, covers 21.5% of residents in 628 counties. The Very Low category for community resilience includes 628 US counties and 18.6% of recorded US residents. The county’s Very High group contains 4 hazards: earthquakes, lightning, riverine flooding, wildfires. The local Relatively High hazard group contains 5 entries: avalanches, coastal flooding, heat waves, landslides, tornadoes. FEMA assigns Relatively Moderate to 3 hazards here, covering hail, strong wind, winter weather. Across the county’s hazard ratings, 2 carry Relatively Low: drought, tsunamis. Across the county’s hazard ratings, 1 carry Very Low: cold waves.