An elevated number of tornadoes in the U.S. contributed to a substantive list of global natural catastrophes in April, according to Aon’s latest monthly Global Catastrophe Recap report. Standout storms also included the strongest cyclone to hit Mozambique on record and costly seasonal flooding in eastern Canada that inundated nearly 10,000 homes.

Regarding U.S. storm events during April, the report noted that nearly 250 tornadoes touched down—the most for the month of April since 2011—which will have an economic cost in the multiple billions of dollars.

Aon’s report noted a number of major U.S. storms in April, including:

• From April 13-15, a major tornado outbreak swept across southern and eastern sections of the U.S., killing at least nine people and causing widespread damage. The outbreak was marked by 70 tornado touchdowns, up to baseball-sized hail, and damaging straight-line winds gusting to 100 mph (160 kph) across the hardest-hit states of Texas, Louisiana, Arkansas, Mississippi and further eastward into the Midwest, Southeast and Mid-Atlantic. Total economic losses were estimated at up to $925 million, with insurers covering approximately $700 million of the cost.

• Between April 17-19, a second major tornado outbreak hit central and eastern sections of the U.S., killing at least four people. The outbreak comprised at least 96 tornadoes across a dozen states. Nearly half of the twisters were recorded in Mississippi, while widespread reports of damaging straight-line winds and large hail also occurred. Total economic losses were expected to reach into the hundreds of millions of dollars, with a majority of the costs being insured.

• From April 23-25, another wave of severe weather struck parts of the Plains and Southeast, killing at least five people following 17 tornadoes, damaging winds and flash flooding. The most substantial impacts were felt in Texas and Louisiana, where a statewide state of emergency was declared. Total economic losses were expected to reach into the hundreds of millions. A majority of these costs will be insured.

Steve Bowen, director and meteorologist within Aon’s Impact Forecasting team, said the high cost of the flood events in particular highlights a selective protection gap in mature insurance markets.

“The multibillion-dollar uninsured cost of the flood events – including those in the Missouri, Mississippi, St. Lawrence, Ottawa and Saint John River Basins – has once again exposed the existing protection gap within mature insurance markets for a specific peril,” Bowen said.

He added that best practice approaches toward understanding flood events and encouragement of more coverage should help lower the gap and minimize residents’ financial burdens.

Other major April storms, according to the Aon report:

• Canadian flooding. Increasing temperatures and heavy rainfall during the second half of April and early May exacerbated the seasonal spring flood situation across the St. Lawrence, Ottawa and St. John River Basins in Canada. Up to 10,000 homes experienced flood inundation, with most of the worst impacts registered in southern Quebec. Total economic losses were expected to minimally reach into the hundreds of millions of U.S. dollars. However, due to relatively low flood insurance take-up, a sizable portion of the economic cost was probably uninsured.

• Mozambique cyclone. Cyclone Kenneth made landfall in Northern Mozambique on April 25 as a 220 kph (140 mph) Category 4 storm on the Saffir Simpson Scale – the strongest storm to strike the country in recorded history, which killed at least 48 people in Mozambique and Comoros. Total economic damage was expected to reach well into the millions of U.S. dollars.

• Brazil rainfall. Torrential rainfall in Rio de Janeiro, Brazil, killed at least 10 people and damaged residential and commercial properties, vehicles and infrastructure. Economic damage was forecast in the millions (USD).

• South African flooding. The South African provinces of KwaZulu-Natal, Eastern Cape and the Free State were hit by widespread flooding and mudslides following heavy rainfall between April 22-24. At least 87 people died, and local infrastructure suffered major damage. The economic cost in Durban alone was ZAR660 million (US$50 million), while the overall tally will be even higher.

• Pakistan rainfall. Heavy rains and flash flooding hit northwestern Pakistan on April 9, killing at least eight people. Northwestern and southern Pakistan experienced more heavy rains and flash flooding on April 13-14, when at least 20 people were killed.

• Severe weather in Afghanistan, Pakistan and India. A storm system – known locally as a western disturbance – resulted in numerous clusters of thunderstorms across parts of Afghanistan, Pakistan and northern India, killing at least 146 people. The storms caused extensive damage to residential and commercial property, infrastructure, and cropland and are likely to costs millions of dollars in economic losses.

The report noted that there were 374 fatalities reported across the globe due to flooding and severe weather events in April.

Source: Aon’s Impact Forecasting

*A version of this story ran previously in our sister publication Insurance Journal.