Many U.S. insurers face a multi-billion-dollar payout from May’s convective storms, which spawned extensive hail, tornado, wind and flood damage across a series of separate events during the month, according to broker Aon plc in the latest edition of its monthly “Global Catastrophe Recap” report.

Of note was a severe storm that swept across the Plains, Lower and Middle Mississippi Valley, Southeast and Mid-Atlantic sections of the country from May 3-5, with combined economic losses in excess of $850 million, said Aon, noting, however, that most of the hail and wind-related damage is insured.

In addition, a series of frontal systems resulted in widespread severe weather from May 6-11, bringing large hail, damaging straight-line winds, tornadoes and flooding to parts of the Plains, Middle and Lower Mississippi Valley and Southeast. Total economic losses were estimated at up to $350 million.

On May 17, flash flood emergencies were issued for localities in southeastern Texas and southern Louisiana. Concurrently, daily severe storms generated damaging hail, strong straight-line winds and brief tornadoes, said the report. Total economic losses from the severe weather and flooding on this day were estimated at $1.1 billion, with a large portion of the flood-related damage in Louisiana likely to be uninsured.

Meanwhile, two tropical cyclones hit India during the month. Cyclone Tauktae made landfall on May 17 in the Indian state of Gujarat as a Category 3-equivalent hurricane on the Saffir-Simpson Hurricane Wind Scale. At least 198 people were killed in India and Sri Lanka, with an estimated economic cost of $1.5 billion. As a Category 1 equivalent storm, Cyclone Yaas made landfall on May 26, causing at least 19 fatalities and damage or destruction to more than 325,000 homes. Yaas affected the states of Odisha and West Bengal, with economic losses in West Bengal alone estimated at INR200 billion ($2.7 billion).

“Natural catastrophes continued to bring notable impacts to areas around the world in May, which is often the start of a transition towards tropical cyclone season in the Northern Hemisphere. While most focus is on the Atlantic Ocean, the most activity last month was found in the North Indian Ocean as two cyclones struck the east and west coasts of India in a matter of days,” said Michal Lörinc, senior catastrophe analyst for Aon’s Impact Forecasting team.

Other global natural hazard events during the month of May include:

• Heavy rainfall associated, influenced by La Niña, brought continued flooding along tributaries of the Amazon River in the Brazilian state of Amazonas. The flooding affected thousands of structures and inundated vast expanses of agricultural land.
• A prolonged stretch of rainfall in mid-May affected multiple countries in Central Europe. The event resulted in one fatality and damage to several thousands of properties, located mostly in rural communities. Aggregated economic losses were expected in the tens of millions of euros.
• A volcanic eruption on Mount Nyiragongo occurred in the Democratic Republic of the Congo on May 22. Lava reached the city of Goma, prompting thousands of people to evacuate. At least 32 people were killed, and hundreds of homes were destroyed by the lava flow.
• Two separate strong earthquakes struck China on May 21 and 22. A magnitude-6.1 tremor in Yunnan Province near Dali City killed three people and caused extensive damage to roughly 13,000 structures. Preliminary economic losses were listed at approximately $50 million. The impact of a magnitude-7.3 event in Qinghai Province was relatively minor, having occurred in a sparsely populated region. Nevertheless, roughly 8,200 structures were damaged or destroyed.
• Incessant rains from May 29 to June 1 triggered “one-in-100-year” floods in New Zealand’s Canterbury Region, with additional impacts seen in the West Coast, Auckland and Otago. In addition to an extensive area of farmland left inundated, preliminary reports cited that thousands of homes, roads and bridges were either damaged or destroyed. Total economic losses were likely to run into the tens of millions of U.S. dollars.

Photograph: This Monday, May, 24, 2021, satellite image provided by NASA shows Cyclone Yaas approaching India’s eastern coast. Photo credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS) via AP.

*This story ran previously in our sister publication Insurance Journal.