More Than insurer RSA today revealed a £50 million hit after the UK's dire summer weather resulted in more than 6,500 claims since June alone.
The wettest June on record landed the group with a £40 million bill while it expects to suffer another £10 million hit so far in July as Britain continues to be battered by rain.
It said the East Midlands, North East and North West were the worst-affected areas, suffering storm damage, flooding and even hail stones the size of golf balls.
RSA, which operates in 140 countries, also revealed a £35 million impact from claims relating to the two earthquakes in Italy in May.
RSA said more than half its weather-related UK claims have already been settled.
The group's combined operating ratio, which shows claims and expenses as a percentage of premium income - where a figure below 100% means a profit is being made - has been affected by the recent claim losses.
RSA said it is now expected to be "better than" 96%, against 95% previously.
While the UK has seen record rainfall since April, RSA said this year's weather claims fall far short of the company's £120 million bill from the widespread flood damage seen in 2007.
But RSA shares fell by about 3% after news of the claims bill.
The group recently revealed it was also suffering from a "dysfunctional" motor insurance market after reporting a 17% slump in the division's premiums during the first quarter of 2012.
It is focusing on more profitable areas in the UK, such as pet and household insurance, while operations in emerging markets are also helping offset tougher domestic markets.
RSA, which employs 23,000 staff, has major operations in countries such as Canada, Ireland and Scandinavia, as well as across regions including Asia and Latin America.