DALLAS — The threat of rolling blackouts, constant strain on the Texas electric grid and hunkering down indoors to avoid the relentless summer heat may soon be sweaty memories as the state’s vicious heat wave appears to be letting up.

A cool front crossing the state Sunday was expected to lower temperatures across Texas this week, lessening the demand on the state’s electric grid.

The change comes just as Texans step outside to fire up barbecue grills, splash in pools and shop on Labor Day.

“If lower temps hold, we’re out of the woods,” said Theresa Gage, a spokeswoman for the Electric Reliability Council of Texas, which operates the state’s bulk transmission grid.

After a brutal summer of afternoons with temperatures topping 100 degrees, a northern wind shift is expected to bring considerably less heat — with highs in the upper 80s Monday dropping to the 50s and 60s in the wee morning hours — from the Dallas-Fort Worth area, south through Austin and Houston, according to the National Weather Service.

This year Texans have endured a record-setting drought, voracious wildfires and sweltering triple-digit heat that has tested the limits of the state’s electric grid several times this summer.

On several occasions ERCOT implemented emergency measures that called on Texans to conserve electricity while the grid operator was at times forced to draw on additional power from Mexico’s grid and ask large industrial and commercial users to voluntarily go without power temporarily. The moves helped avoid rolling blackouts.

“Nothing has quite the effect on electric usage as extreme heat,” Gage said. “It took us all to get through this difficult summer.”

Lee Glover, a horticulturalist who checks landscaping jobs for a suburban Dallas nursery, called the summer heat merciless, joking that he’ll have to find his jacket when temperatures consistently dip below 100 degrees.

“It’s going to bring much relief,” Glover said, “Not only to us, it will bring relief to the plants themselves. Even if it’s just 10 degrees [cooler] it will make a huge difference.” Austin set its all-time record when the mercury rose to 112 degrees on Aug. 28, the latest among numerous triple-digit records set across Texas in recent months.

Texas just finished its hottest June-through-August on record — and soon could hold that spot nationally when official numbers are tallied later this week. Estimates show temperatures during this span averaged 86.7 degrees, topping the previous record of 84.3 set in 1980 and tied in 1998.

Electricity usage has risen along with the temperatures, with an all-time peak demand for power reached Aug. 3 at 68,294 megawatts.

Printed on September 6, 2011 as: Summer heat wave seemingly subsiding