Harris County, TX climate risk

Harris County in the state and national rankings

At about $2.22 billion, modeled expected annual loss in Harris County ranks #4 of 3,232 across the US. A #1 of 254 state ranking accompanies its 18.0% share of the Texas loss total. About $2.22 billion is the modeled yearly average over the long run, rather than a one-year prediction. Riverside County, CA ranks immediately above it, with about $2.27 billion in modeled annual loss. The next lower national total is about $2.20 billion, in Maricopa County, AZ. At about $973.2 million, Dallas County, TX is one place lower in the state loss ordering. Its 7.9% state loss share accompanies an estimate about $1.24 billion away from this county’s total.

Texas county comparisons

Harris County hazard estimates

Riverine Flood

For riverine flooding, about $1.12 billion in expected annual loss puts the county #3 of 3,232 across the US. This hazard makes up 50.6% of the total; FEMA assigns a Very High rating, and its loss ranks #1 of 254 in Texas; the same rating for riverine flooding covers 3 Texas counties and 26 across the US.

Hurricane

No US county has more modeled annual loss from hurricanes; this estimate of about $457.9 million ranks #1 of 2,485. At 20.6% of the county’s modeled loss, the hazard places #1 of 250 statewide; FEMA assigns a Very High rating; for hurricanes, 5 state counties and 47 US counties share that label.

Tornado

FEMA models about $407.4 million in expected annual loss from tornadoes, placing the county #2 of 3,225 nationally. This hazard makes up 18.4% of the total; FEMA assigns a Very High rating, and its loss ranks #2 of 254 in Texas; for tornadoes, 9 state counties and 37 US counties share that label.

Cold Wave

The national loss rank for cold waves is #3 of 3,232, based on about $118.1 million in modeled expected annual loss. At 5.3% of the county’s modeled loss, the hazard places #1 of 254 statewide; FEMA assigns a Very High rating; the same rating for cold waves covers 7 Texas counties and 39 across the US.

Heat Wave

The national loss rank for heat waves is #9 of 3,202, based on about $80.4 million in modeled expected annual loss. At 3.6% of the county’s modeled loss, the hazard places #2 of 254 statewide; FEMA assigns a Very High rating; the Very High label covers 2 state counties and 11 nationally for heat waves.

Lightning

FEMA models about $8.6 million in expected annual loss from lightning, placing the county #6 of 3,222 nationally. This hazard makes up 0.4% of the total; FEMA assigns a Very High rating, and its loss ranks #1 of 254 in Texas, matching 109 US counties, including 12 in Texas, for this hazard.

About $664.2 million separates riverine flooding from hurricanes in the local estimates, equivalent to 30.0 percentage points of county loss. For hurricanes, modeled loss is about $50.5 million above tornadoes, leaving 2.3 percentage points between their county shares. About $289.3 million separates tornadoes from cold waves in the local estimates, equivalent to 13.0 percentage points of county loss. The loss estimate for cold waves exceeds heat waves by about $37.8 million, equivalent to 1.7 percentage points of total loss. The loss estimate for heat waves exceeds lightning by about $71.8 million, equivalent to 3.2 percentage points of total loss.

Population and recorded values

FEMA counts 4,726,200 residents in Harris County, across about 1,795 square miles. About $838.84 billion is the building value amount in FEMA’s record. FEMA lists about $65.1 million in agricultural value. Per resident, the modeled annual amount is about $469; the Texas average is about $424. The county holds 16.2% of the state population, compared with 18.0% of modeled loss. The county contains 15.8% of the building value recorded across Texas. By recorded residents per square mile, the county places 2 among 254 Texas county records with population and area values. Those recorded totals give about 2,632 residents per square mile, versus about 107 across Texas. At 4,726,200 residents, the county compares with the Texas county median of about 18,439. In the US totals, the county represents 1.4% of modeled annual loss and 1.4% of recorded residents. Per-person modeled loss is about $469 locally; the corresponding US average comes to about $459. The six hazards described above together make up 98.9% of modeled loss, about $2.19 billion annually. Other hazards account for the remaining 1.1% of modeled loss, about $23.3 million. About $7.7 million places strong wind at number 7 in the local loss list and #2 of 254 within Texas. This 0.3% slice of county loss ranks #43 of 3,225 across US counties. The county’s number 8 hazard by dollar loss is earthquakes: about $5.9 million, with a state rank of #1 of 254. With 0.3% of county loss, this hazard has national placement #319 of 3,232.

FEMA labels and risk score

Harris County has a FEMA risk index score of about 99.9, ranking #3 of 3,144 nationally. FEMA labels risk index as Very High, matching 2 county records across Texas. For expected annual loss, FEMA assigns Very High; 1 county in Texas has that label. The social vulnerability rating is Relatively High, a label shared by 74 of 254 Texas counties. For community resilience, FEMA assigns Very Low; 106 counties in Texas have that label. Its risk score ranks #1 of 254 within Texas, while its loss total ranks #1 of 254. This combination, Relatively High for vulnerability and Very Low for resilience, occurs in 29 counties in Texas. The group represents 20.2% of statewide loss; this county supplies 88.8% of the group’s modeled amount. The adjacent state score below this county belongs to Dallas County, TX: about 99.7, ranked #2 of 254. That comparison county holds a Very High risk index rating and 7.9% of Texas modeled annual loss. The Relatively High category for social vulnerability includes 630 US counties and 15.4% of recorded US residents. FEMA lists 628 county records with Very Low community resilience; together they contain 18.6% of its US population total. The local Very High hazard group contains 8 entries: cold waves, heat waves, hurricanes, ice storms, lightning, riverine flooding, strong wind, tornadoes. FEMA assigns Relatively High to 2 hazards here, covering coastal flooding, winter weather. The local Relatively Moderate hazard group contains 4 entries: drought, earthquakes, hail, landslides. Across the county’s hazard ratings, 1 carry Relatively Low: wildfires.