The cost of Sydney's December hailstorms is approaching $400 million. Two months after the storms swept through Sydney's western suburbs, the Insurance Council of Australia (ICA) estimates insured losses at $370 million from 53,000 claims.

About 63% of the claims were for motor vehicle damage, with most of the rest property and commercial claims.

While not as widespread as the infamous 1999 Sydney Hailstorms - Australia's third most costly event with $3.3 billion in insured damages - reports on the ground suggest the destruction in some isolated pockets was just as severe.

Storms in the Northern Rivers region of NSW last month are expected to cost insurers a further $10 million. Insurers have received more than 1500 claims.