Global insured catastrophe losses totalled $US17 billion ($25.69 billion) in the first quarter, slightly above the century average, according to Aon.

The broker’s latest catastrophe report notes severe convective and winter storms in the US were the leading cause of costs, with four events posting billion-dollar losses.

Windstorms and flooding in Europe, and winter weather in east Asia also had an impact.  

The loss figure is well below first-quarter insured costs in the past three years, which have averaged $US27.33 billion ($41.32 billion).

Insured losses from the 7.5-magnitude Noto earthquake, which hit Japan on New Year’s Day, were reported to exceed $US1 billion ($1.51 billion), with more than 120,000 claims made.

The quake was also the deadliest event, with 245 fatalities, and the costliest event by economic loss at $US17.6 billion ($26.60 billion).

Overall economic losses were $US45 billion ($68 billion), well below the century average of $US59 billion ($89.16 billion). Aon estimates the insurance protection gap for the first quarter was 64%.  

The report says deaths from catastrophes were below the century average, at about 1500. 

Aon warns of a sharp increase in losses after forecasters warned of an “aggressive” Atlantic hurricane season. Selected forecasts from the US point to an above-average season, with some predicting 11 hurricanes will form.