As an overnight low, that temperature is more typical of April or October in Denton, not July. Yet, that’s how far the mercury dipped overnight on July 3 at Denton Enterprise Airport.
Overnight lows had been cool enough this week to flirt with records, but none were broken, officially, for the Dallas-Fort Worth area. Denton records don’t go back far enough to know whether Monday’s 61 degrees, Tuesday’s 59 degrees or Thursday’s 63 degrees broke a record here, according to Jesse Moore, meteorologist with the National Weather Service in Fort Worth.
Typically, overnight lows are in the 70s this time of year, Moore said. Part of the reason North Texas was cooler this week was because a high-pressure ridge, which brought high temperatures at the beginning of June, had shifted to the west. Northerly winds could travel all the way to Texas and did, bringing several cool fronts with them in June and this first week of July.
The northerly winds also kept the humidity low, so that when daytime temperatures soared, the heat was less noticeable, Moore said.
The cooler overnight temperatures could be good for ratepayers, said Brian Daskam, spokesman for Denton Municipal Electric. Overall, the utility has seen lower peak loads on its electric grid compared to last summer. For example, June 2012 saw a peak load of 323 megawatts, versus 318 megawatts in June 2013. And, even though the high temperature on the Fourth of July was just three degrees less this year, the peak load was 23 megawatts less.
“That probably results in lower electric bills for our customers,” Daskam said. “And as a publicly owned utility, we’re happy about that.”
Pleasant weather likely helped the region’s air quality, too, as many monitors around the Dallas-Fort Worth area for the past five weeks saw ozone levels not only below the old standard of an eight-hour average of 85 parts per billion but also below a new standard, too.
A new eight-hour standard of an average 75 ppb goes into effect in 2018. According to state records, monitors at Denton Enterprise Airport and Grapevine Fairway are tied with the highest readings, currently running a three-year average of 82 ppb.
However, that shift of high pressure that brought relief to North Texas also meant record-breaking temperatures for the Southwest. In Death Valley on Sunday, the high temperature reached 129 degrees, the hottest temperature ever recorded in June in the United States, according to the weather service.
Despite the cool spells of the past five weeks and the cooler-than-normal spring leading up to June, the average temperature for June overall was 1.3 degrees above normal, Moore said. Climatologists found that Texas was more likely to have a hotter-than-normal summer this year. The heat and humidity more typical of a North Texas summer should return this weekend, as the high-pressure ridge builds east and rain chances diminish. Highs are expected to reach the mid-90s, with a slight dip on Monday to 92.
The relative humidity is expected to climb, too, from 30 percent today to 44 percent by Monday, which means those 92 degrees will feel a few degrees hotter still.
PEGGY HEINKEL-WOLFE can be reached at 940-566-6881 and via Twitter at @phwolfeDRC.