The average cost of heating oil rose 89 cents in one week, according state data updated Thursday.

Across the state, the cost of a gallon of heating oil averaged $4.83 as of Monday, according to the Maine Department of Energy Resources. That’s a roughly 22.6% spike since March 2.

During that same period, kerosene prices rose 16.9% to an average of $5.80. Propane was up about 1.8%, averaging $3.42 across the state, according to the department.

Prices had already ticked up at the beginning of the month after Israel and the United States launched attacks on Iran, sending shockwaves through the global oil market.

In Greater Portland, a gallon of heating oil ran $4.88 on Monday.

Dan Burgess, the department’s acting commissioner, said in a written statement that Maine has for years worked to reduce residents’ dependency on heating oil and that “this conflict again underscores why it is imperative we reduce our exposure to volatile global energy markets.”

About half of all Maine households relied on oil as their primary source of heat in 2024, the latest year for which data is available. That was the lowest proportion reported in decades.

Heating oil prices have continued to shift daily, according to an analysis of data aggregated by MaineOil.com, which records prices at sellers throughout the state several times each week. Among 30 sellers’ prices recorded Thursday, the statewide average was $4.63.

In Greater Portland, it was $4.59, based on prices reported from nine sellers.

ASSISTANCE AVAILABLE

In light of the increase, MaineHousing is reminding residents that they can apply for the Home Energy Assistance Program, or HEAP. Applications are open until May 29, the housing authority said in a Thursday announcement.

HEAP helps low- and moderate-income households pay for a portion of their home heating costs.

They warned that demand could increase significantly amid the war in Iran.

“MaineHousing and our community action agency partners across Maine stand ready to help as we head through the final weeks of winter and energy prices continue to climb,” Director Dan Brennan said in a written statement.

Meanwhile, applications for the state’s Energy Crisis Intervention Program remain open until April 30.

That program provides one-time payments of up to $500 for households without heat or with less than a week’s supply of fuel. It is open to households that are already eligible for HEAP.

“We know spring is approaching, and warmer days are ahead,” Brennan said. “But now is the time to apply for heating assistance if you haven’t already.”