Updated from 12:23 p.m. EDTOil prices rose Monday as Israel's moratorium on air strikes in Lebanon proved short-lived. Natural gas staged its biggest rally this year, meanwhile, on concerns that a heat wave in the U.S. will push up electricity consumption. September crude added $1.16 to $74.40 a barrel after Israel jets struck southern Lebanon Monday in support of ground troops fighting Hezbollah. The attacks came 12 hours after Israel announced a 48-hour cessation of bombing raids, a pledge it said depended on military developments on the ground. Forecasts of hot weather in the Northeast sent natural gas up $1.02, or 14%, to $8.21 per million British thermal units. The fuel is used by some utilities to generate electricity. A heat wave moved into the Midwest and Northeast Monday, driving up temperatures to the high 90s and low 100s. On Tuesday, temperatures in those regions are expected to eclipse the highs seen two weeks ago and may set records. A cold front will provide some relief from scorching temperatures and high humidity by the end of the week, according to AccuWeather, a forecaster in State College, Pa. Hot weather has plagued the western U.S. for the past two weeks and contributed to a surprising drawdown in stockpiles the previous week. Inventories usually rise by an average of 65 billion cubic feet during the summer. Booming demand hit a fresh record of 96,314 gigawatt hours of electricity for the week ended July 22, over 1% higher than last year, according to the Edison Electric Institute in Washington, DC. Heating oil jumped 2 cents to $1.96 a gallon and wholesale gasoline was up 4 cents at $2.28 a gallon. Prices of gasoline and heating oil for delivery in August were volatile today because the contracts come due today. On Sunday, Israel agreed to a 48-hour bombing moratorium after a raid on the Lebanese village of Qana killed as many as 60 people, many of them children. The attack made Sunday the deadliest day yet in the two-week conflict, which has killed upwards of 500 people. Earlier Monday, oil prices fell below $73 a barrel after U.S. Secretary of State Condoleezza Rice indicated a ceasefire resolution could be hammered out in the U.N. Security Council by this week. But Israel's prime minister rejected international pressure to halt its aerial bombardment until its two kidnapped soldiers are released. The war was started over Hezbollah's abduction of the two. "The fighting continues. There is no ceasefire and there will not be any ceasefire in the coming days," said Israeli Prime Minister Ehud Olmert, according to the BBC. Israeli officials have said they would not halt the fighting until an international peacekeeping force arrives in the area. Later this week, the U.N. Security Council is set to discuss sending in an international force, which could be dispatched as early as next week.