Insurers face multibillion-dollar payouts after a prolonged run of storms pushed US tornado numbers to a four-year high in May, according to Aon’s monthly Global Catastrophe Recap.

US insurance payouts are expected to pass $US10 billion ($14.33 billion) this year, for a 12th consecutive year, the report says.

Seven outbreaks of severe convective storms swept across central and eastern US last month, with nearly 4400 individual reports. Multi-day outbreaks resulted in 362 tornadoes – the most since 2015 – plus large hail, damaging straight-line winds and record-breaking rainfall, which damaged property and agriculture.

Record-breaking rainfall in Oklahoma and Kansas brought historic flooding across the Arkansas River Basin, accompanied by remnant flooding in the Missouri and Mississippi basins.

Elsewhere last month, drought conditions in China’s Yunnan province affected more than 273,000 hectares of crops at a financial cost of 953 million yuan ($404.86 million).

Prolonged rainfall affected much of Paraguay, leading to widespread flooding that killed at least six people, led to the evacuation of more than 40,000 residents and harmed the cattle industry.

In southern Europe, rainfall caused rivers to overflow in Italy’s Emilia-Romagna region, inundating about 600 homes and businesses and agricultural land. The same weather system affected the Balkans.

The Arabian Peninsula and Tanzania also endured heavy rainfall.