Storms in the US led to insured losses of more than $US1 billion ($1.07 billion) last month, according to Aon Benfield subsidiary Impact Forecasting.

One five-day period of severe weather saw baseball-sized hail and 110kmh winds damage homes, businesses and cars in Chicago and Denver and surrounding regions.

The Rocky Mountain Insurance Information Association estimated nearly $US110 million ($117.91 million) of insured losses in Colorado alone.

In a separate event, from May 10-15, large hail, flash floods and winds caused heavy damage and nine-figure insured losses in Illinois, Indiana, Ohio, Missouri, Kansas and Nebraska.

“Despite the relatively low activity of the tornado season, insurers are still faced with several billions of dollars in storm-related damage claims,” Associate Director and Meteorologist Steve Bowen said.

At the end of last month US tornado activity ranked in the bottom 25% for all years dating back to the early 1950s, Mr Bowen says.

Meanwhile, an earthquake in Thailand that killed at least one person and injured 23 led to insured losses of $US15 million ($16.07 million), according to Impact’s monthly round-up.