US insurance giant Allstate was hit with a $42mn reserve charge last month, taking its total July catastrophe bill to $262mn after a month that was scarred by wildfires and summer storms.

The insurance giant suffered an estimated $220mn of pre-tax losses in the period stemming from 15 separate events.

Allstate said the Carr fire in Northern California and two severe hail events - which mainly impacted the state of Colorado - accounted for 75 percent of the total loss bill.

The personal lines heavyweight said total cat losses for the month were $207mn after-tax. In June, Allstate suffered $384mn in catastrophe losses.

According to estimates by broker Aon, the Carr wildfire is expected to cost insurers upwards of $1bn, while rating agency Moody’s pegged insured losses stemming from the wildfires at $1.5bn.

Rival AmBest matched Moody’s estimates of $1.5bn and said while it is still too early to determine the full impact of the wildfires, based on acreage and the number of fires to date, 2018 may produce greater losses for insurers than 2017 which was the costliest year on record for the peril

The fire broke out on 23 July in Shasta County, California, spreading east and then south later in the week.