A typical Oahu electric bill jumped $7.42 in February from the previous month due to higher fuel prices and purchased power costs.

Hawaiian Electric Co.’s bill for an Oahu household using 500 kilowatt-hours is $142.81, or 26.5 cents a kilowatt-hour this month. The bill in January was $135.39, or 25 cents a kilowatt-hour. In December the bill was $132.32, or 24.4 cents a kilowatt-hour.

HECO spokeswoman Shannon Tangonan said in an email that the increase was due to “higher purchased power costs and higher fuel costs.”

February’s bill makes the fourth straight month of increases, following two months of minor reductions in electricity prices.

The cost of electricity in the state is double the national average.

Hawaii residents paid an average of 28.48 cents a kilowatt-hour in November. The national average was 12.75 cents in the same month, according to the latest figures from the U.S. Energy Information Administration.

Hawaii’s high rates are largely due to the state’s use of imported oil for most of its power. In 2014, Hawaii spent $5.4 billion on petroleum, according to the EIA.

Other states use a mix of energy resources, which include natural gas, hydroelectric power, coal and nuclear power.

In 2015 HECO’s energy mix was roughly 71.1 percent oil on Oahu. HECO imports oil primarily from Southeast Asia and the Middle East.

Contrary to Oahu, some neighbor island bills slightly shrank in February.

The residential rate for Hawaii Electric Light Co. customers on Hawaii island was $162.87, or 30.2 cents a kilowatt-hour. The bill in January was $163.27, or 30.3 cents a kilowatt-hour.

Maui Electric Co. customers also saw a decrease.

The average bill for a Maui household using 500 kilowatt-hours is $143.65, or 26.8 cents a kilowatt-hour. In January, the bill was $146.59, or 27.4 cents a kilowatt-­hour.

Customers on Molokai and Lanai paid higher bills in February compared with January.

MECO customers on Molokai using 400 kilowatt-hours of electricity are paying an average of $137.70, or 32.0 cents a kilowatt-hour. In January, it was $137.11, or 31.8 cents a kilowatt-hour.

Lanai residents using 400 kilowatt-hours of electricity on the island are paying $142.24, or 33.1 cents a kilowatt-hour. For January, the bill was $139.67, or 32.5 cents a kilowatt-hour.

Bills on Lanai and Molokai are calculated based on a typical household using 400 kilowatt-hours of electricity in a month. This is due to lower energy use compared with Maui, the Big Island and Oahu, HECO said.

HECO, MECO and HELCO monthly bills include the cost for kilowatt-­hours used plus other charges.

The Kauai Island Utility Cooperative’s rate increased to 32.80 cents a kilowatt-hour in February. In January, the rate was 32.77 cents a kilowatt-hour. The typical bill for a household using 500 kilowatt-hours in February, including a $10.58 customer base charge, is $174.58.