Hurricane Idalia could cause or exacerbate major problems in the Florida insurance market. With predicted insured losses ranging from $4.05 to more than $25 billion, the storm could end up forcing Citizens, the state’s insurer-of-last-resort, to use “special assessments” to recover losses from policyholders around the state. “If someone is paying $3,000 [in annual premiums], they can force you to write another for $1,200 or $1,300. Imagine people’s shock when that shows up at their door,” Jeff Brandes, a former Florida state senator and president of the Florida Policy Project, told Heatmap.

Citizens’ portfolio has ballooned — from fewer than 500,000 policyholders and $877 million in premiums in 2019, to an estimated 1.7 million policyholders with $5.1 billion in premiums this year — as private insurance firms have abandoned the state in the face of mounting climate-fueled risks. In Hillsborough County, home to Tampa, just 20% of homeowners have flood insurance, in Taylor County, where Idalia made landfall, that share is just 5.4%. “Translation,” Steve Bowen, of Gallagher Re, wrote on Twitter, “A lot of uninsured exposure for water-related damage.” (Citizens: Heatmap $; Cost estimates: Reuters, New York Times $; Uninsured losses: Bloomberg $, Heatmap $; Climate change and insurance: The Hill, CNBC; Climate Signals background: Hurricanes)