October residential electricity rates will rise in all counties, reflecting price gains in crude oil in recent months.

Hawaiian Electric Co. said the typical 600-kilowatt-hour bill for O'ahu residential customers will increase to $147.64 from $140.81 in September.

The effective rate for electricity in Honolulu is rising to 23.10 cents per kilowatt hour from 22.80 charged last month.

Hawaiian Electric said the rate for O'ahu is still below the 32.5 cents per kilowatt hour paid in September 2008, when the effects of record high oil prices were being felt.

Elsewhere in the state:

• Maui customers will see their rates decline to 26.29 cents from 25.16 cents that Maui Electric Co. charged residential customers in September. The typical Maui bill will be $165.76.

• Big Island residential rates will rise to 32.54 cents from the 31.93 cents per kilowatt hour in August. The typical bill will be $206.35.

• Kaua'i Island Utility Cooperative's October rate is rising slightly to 32.07,from the 32.03 cents charged last month.

On O'ahu, rates peaked in September 2008, when residential customers' monthly bill averaged $202.13.

Most of Hawai'i's electricity is produced using petroleum products such as fuel oil or diesel oil. Each month, electricity costs vary because of adjustments for fuel costs.

There typically is a lag when petroleum prices increase because utilities must first use up inventory bought at lower prices.