Last year saw the highest costs from natural disasters since 2012, with two earthquakes in Japan in April accounting for the heaviest losses, a leading insurer has said.

Losses from natural disasters worldwide totalled $175bn (£142bn) last year, some $50bn of which was covered by insurance, Munich Re said in an annual survey on Wednesday.

The earthquakes on Japan’s southern Kyushu island caused $31bn worth of damage, with $6bn of the costs covered by insurance. Floods in China in June and July caused $20bn in costs, only $300m of which was insured.

The third-costliest disaster was Hurricane Matthew, which hit the Caribbean and the eastern US in October. It incurred losses totalling $10.2bn, of which $3.8bn was covered by insurance.

In 2015, when the El Niño weather phenomenon reduced hurricane activity in the North Atlantic, global natural disaster losses totalled $103bn, $32bn of that sum insured. However, the number of people killed dropped to 8,700 last year from 25,400 the previous year.

Last year’s losses were “in the mid-range” after three years of relatively low costs, Munich Re board member Torsten Jeworrek said in a statement. He stressed that “losses in a single year are obviously random and cannot be seen as a trend”.

The company said there was an “exceptional” number of floods, which accounted for 34% of overall losses, compared with an average of 21% over the past decade.

Those included $6bn in losses, about half of them insured, resulting from storms and flooding in Europe – particularly in Germany and the Paris region – in May and June.

Jeworrek said that “the high percentage of uninsured losses, especially in emerging markets and developing countries, remains a concern”.