Insurers are set to pay out a record $US135 billion ($172 billion) to cover losses from natural disasters in 2017, the world's largest reinsurer said, driven by the costliest hurricane season ever in the United States and widespread flooding in South Asia.

Overall losses, including uninsured damage, came to $US330 billion, according to the reinsurer, Munich Re of Germany. That tally was second only to 2011, when an earthquake and tsunami in Japan contributed to losses of $US354 billion at today's dollars.

Insured losses from weather-related disasters were at a high, making up most of the $US135 billion. Munich Re executives warned that losses would continue to escalate.

"Some of the catastrophic events, such as the series of three extremely damaging hurricanes, or the very severe flooding in South Asia after extraordinarily heavy monsoon rains, are giving us a foretaste of what is to come," Torsten Jeworrek, a Munich Re board member, said in a statement.