Flooding, a 7.7 magnitude earthquake and tsunami combination, and a super typhoon highlighted what was a busy October for catastrophes, in what has already been an active year, Aon Benfield said in a new report.

"The breadth of natural catastrophes occurring this month is a continuation of an already active year in terms of global activity," said Steve Jakubowski, president of Impact Forecasting, Aon Benfield, in a statement.

In the U.S., October saw the second strongest non-tropical or post-tropical low pressure system ever recorded in the continental U.S., Aon Benfield said. The system brought "severe weather, extremely gusty winds, torrential rains and heavy snows to eastern sections of the country" between Oct. 25 and Oct. 28. Multiple tornadoes touched down in Illinois and damaging wind was reported across Missouri, Illinois and Wisconsin.

The system then brought clusters of thunderstorms across the Great Lakes and Ohio Valley before later affecting the Tennessee Valley and the Southeast. Aon Benfield said at least 52 separate tornado touchdowns were confirmed. The system then pushed east, with severe weather affecting North Carolina, Georgia, Virginia and Maryland. "Behind the front, near-blizzard conditions occurred in the Dakotas," Aon Benfield said. The system caused "millions" in damages, according to Aon Benfield.

Also in the U.S., severe weather on Oct. 5 caused thunderstorms and torrential rains in Phoenix. Oct. 6 saw tornadoes in the northern part of Arizona. Aon Benfield said this system caused over $1.25 billion in damages.

Another system from Oct. 22 to Oct. 24 brought wind and hail across northeast Texas, Arkansas, Mississippi, Alabama, southern Tennessee and northern Georgia, causing "millions" in damages, Aon Benfield said.

Elsewhere in the world, a 7.7 magnitude earthquake hit western Indonesia, triggering a large tsunami that reportedly reached 1,968 feet inland. Within 24 hours, Mount Merapi erupted on the provincial border of Central Java and Yogyakarta, shooting ash over almost a mile into the air before covering in excess of 30,000 homes in hot ash. Aon Benfield said damages were listed at $16.8 million.

A trio of hurricanes hit the Caribbean, with Hurricane Paula causing minimal damage, Hurricane Richard causing economic losses of $24.5 million, and Hurricane Tomas, which is still active, causing losses expected to exceed $12.8 million so far.

Back to Asia, heavy rains from Tropical Depression Fourteen and other tropical moisture caused the worst rains in China since 1961, triggering floods that damaged or destroyed over 50,000 homes and other structures. Total economic losses were listed at $169 million, Aon Benfield said.

Monsoon rains and flooding also impacted Indonesia's West Papua, Vietnam, Thailand, Cambodia and Japan, with the Vietnam, Thailand and Cambodia floods combining to cause over $1 billion in economic damages.

Super Typhoon Megi also struck the Philippines and China during the month, damaging agricultural, electrical and transportation infrastructures with total economic damages listed at $281 million in the Philippines and $412 million in China, according to Aon Benfield.

Heavy rains and gusty winds in New South Wales, Australia, led to the worst flooding in over 80 years in some locations, Aon Benfield said, with damages estimated at $39 million, most of which is expected to be covered by insurance.

"The powerful earthquake and tsunami in Indonesia; the floods across Asia, Europe, Oceania and Africa; the tropical cyclones in the Atlantic, Pacific and Indian basins; and severe weather across South America in October all highlight the need for [reinsurers and insurers] to keep informed on climatological and meteorological variances," Mr. Jakubowski said.