HOLYOKE, Mass. – New Englanders set a record for electricity usage on Tuesday, and while demand is expected to remain high through the week, slightly cooler temperatures mean the record will likely stand, at least for now, the region’s power grid manager said.

Electricity use in ISO New England Inc.’s six-state region peaked at an average 26,749 megawatts between 2 and 3 p.m. Tuesday, breaking the record of 25,348 megawatts set on Aug. 14, 2002.

Temperatures reached the 90s across much of the region but eased a bit on Wednesday. Electricity use at 11 a.m. Wednesday stood at 23,500 megawatts, said Dominic Slowey, a spokesman for Holyoke-based ISO New England.

The cooling trend was expected to continue through the weekend.

New England’s power grid has about 32,000 megawatts of capacity, but a fraction of the total is typically unavailable because of maintenance.

The grid handled Tuesday’s peak use without any disruptions, and ISO New England did not resort to emergency measures or issue public calls for energy conservation.

“The New England power system was able to withstand this latest heat wave because of improvements made to the system over the past several years,” said Stephen G. Whitley, ISO New England’s senior vice president and chief operating officer.

ISO New England operates the region’s bulk power system and wholesale electricity markets, serving 6.5 million households and businesses.

Elsewhere in the U.S., a blistering heat wave is being blamed for the deaths of at least 13 people in Phoenix, Ariz., prompting officials to ask for donations of ice and water bottles for those sweltering without air conditioning.

Eleven of the victims since Saturday were homeless, and the other two were elderly women, including one whose home cooling system wasn’t on, police said Wednesday.

By comparison, the Arizona Department of Health Services documented 34 heat-related deaths among all Arizona residents last year. The number of illegal immigrants killed by heat-related illnesses while trying to cross the desert are counted separately.

Phoenix has endured above-average temperatures every day since June 29, with a peak of 111 degrees on Tuesday, and a high of 108 was forecast Wednesday. Even during the coolest part of the day, the mercury descended only to 89 Wednesday morning, and some mornings haven’t gone lower than 91.

Also, a drought that is stunting corn, rice and soybean crops across the nation’s Farm Belt is also leading many communities in more urban parts of the Midwest to ban lawn-watering and urge homeowners to conserve.

“I’m not watering out of respect for what is happening ecologically,” said Tod Lending, gesturing toward his the parched front lawn on Chicago’s North Side. “I have a 10-year-old daughter and I’m trying to teach her what the right thing is to do ecologically.”