After three months of intensely hot, dry weather, summer 2015 has gone down as the driest in the Flathead Valley’s history.

The National Weather Service’s official rain gauge at Glacier Park International Airport registered just 1.09 inches of rain during June, July and August.

This year’s summer easily beat out the previous record of 1.40 inches that has stood since 1929 — the year of the famous Half Moon Fire.

In just three days, that fire burned 103,000 acres in a 30-mile swath that cut across Teakettle and Columbia mountains, across the Flathead River, into the Canyon and on to Apgar in Glacier National Park.

By comparison, a host of wildfires have burned 145,000 acres across Northwest Montana this summer.

This summer included the sixth-driest June, the 21st-driest July and the 11th-driest August since 1899 when the Weather Service began keeping records.

Unsurprisingly, the top driest summers double as some of the most brutal fire years: 1910 was the third-driest summer, with 1.50 inches, followed by 2003 and 2007, with 1.66 and 1.82 inches, respectively.

Summer 2015 also was the fifth-warmest on record and included the hottest June and numerous single-day records for high temperatures.

Through August this year, total Flathead Valley precipitation is 6.85 inches, or 4.76 inches below normal.

LeeAnn Allegretto, a meteorologist with the Weather Service’s Missoula office, said the ongoing El Niño event has largely fueled the unusually hot, dry conditions that started as early as last fall.

“This same El Niño event, even in its weak form, gave us the below-normal snowpack that we saw last winter,” Allegretto said. “It was weak, showing signs of life last fall, was noticeable into the winter and spring and that’s put us where we are today, high and dry — and on fire.”

El Niño is a global weather pattern caused by warmer-than-average surface water temperatures in the Pacific Ocean. It typically reroutes the jet stream and other prevailing weather patterns, shifting storm systems away from the Northern Rockies and pushing them north into Canada and south toward Texas, which has had one of its wettest summers.

Allegretto said El Niño events in the past have lasted as long as three years and this event will continue at least through this winter.

“That’s not to say we won’t get our typical cold snaps and dumps of snow,” she added. “But once it’s all tallied up, it will probably be below average.”

A break from the parched conditions, however, could come as soon as this week.

Another cold front is projected to sweep through Northwest Montana this weekend and may dump up to an inch of rain.

Unless the weather pattern shifts, the Weather Service is forecasting slight, scattered precipitation beginning as early as today, giving way to more substantial rain and high-elevation snow over the weekend.

“The pattern looks great, but who gets what is yet to be determined,” Allegretto said. “I would say it’s the first really good, cold, wrapped-up system that we’ve seen in months.”

Reporter Samuel Wilson can be reached at 758-4407 or by email at swilson@dailyinterlake.com.