Bushfires have destroyed at least 21 homes in northern NSW, causing the Insurance Council of Australia (ICA) to declare its second catastrophe in five weeks as drought conditions worsen ahead of summer.

The NSW Rural Fire Service says 32 fires were burning at midday, with 12 uncontained. Property damage includes the loss of 15 homes in the Rappville area near Casino, while the Long Gully Road fire near Tenterfield has destroyed a further six houses.

“The NSW Rural Fire Service is still determining the extent of property damage, and it may take several weeks before insurers are able to quantify the extent of insurance losses,” ICA CEO Rob Whelan said.

“Insurers are standing by to help customers in this region with assessors mobilising to examine properties once it’s safe to do so.”

ICA early last month declared a catastrophe for fires in northern NSW and south-east Queensland which have caused insured losses of $20 million. Insurers have received 300 claims so far from those blazes.

The dry and warm start to spring is likely to continue to the end of the year, increasing the severity of drought and bushfire conditions, the Bureau of Meteorology warned in its October to December outlook.

The high-risk weather is linked to the strongest positive Indian Ocean Dipole (IOD) since 2001, exacerbated by climate influences south of Australia which are also unfavourable.

A positive IOD is characterised by cooler waters to the northwest of Australia and warmer waters further west, usually bringing warmer days and below-average winter and spring rainfall to southern and central regions of the country.

Today’s catastrophe declaration by ICA activates a disaster hotline to assist policyholders and mobilises disaster recovery specialists to support affected property owners and local community groups. An industry taskforce will also identify and address any issues that arise.

“ICA is aware police are investigating whether the Rappville fire was the result of arson, and we can reassure property owners that this will not have an impact on their insurance claims,” Mr Whelan said.

The NSW Department of Primary Industries says that around 97% of the state was affected by one of three drought categories at the end of September.