Summit County may have narrowly missed setting an official record-high temperature on Monday, July 17, but the near-miss shows that the heat wave has finally arrived to Colorado’s Rocky Mountains after making headlines across the northern hemisphere. 

The record high for July 17 was set at 85 degrees in 2010, according to National Weather Service meteorologist Russell Danielson. 

While a weather station east of Dillon recorded a high of 89 degrees on Monday afternoon, according to National Weather Service reports, that data was unofficial. Official stations of record use a strict set of criteria to report data for a geographical area, and the one located in Dillon only recorded a high of 84 degrees, which is one degree shy of the record. 

The factors that come into play while making claims about record temperatures are complicated. A station needs more than 30 years of reputable data before claims can be made about record highs or lows. There is also a one-day delay in reporting official high temperatures since meterologists look at all of the data for the previous 24-hour period around 7 a.m. each day to file their official reports. 

“It’s a very weird thing,” Danielson said of the inner workings of reporting record-breaking temperatures. “Yeah — kind of hard to explain.”

Though temperatures didn’t break records in Summit County this week, there’s potential for records to fall in the coming week. 

A “very strong” high pressure system has moved into the Four Corners area, making its presence known across Colorado, Danielson said, and the system has been historic.

According to the Associated Press, “a relentless streak of temperatures hitting 110 degrees Fahrenheit (43.3 C) or more in Phoenix is poised to smash a record for major U.S. cities, showing that Earth’s ongoing summer swelter is as persistent as it is hot. The stretch of dangerous heat tied the record Monday and is set to reach 19 days on Tuesday.”

Now, Danielson said that heat is blowing into Colorado.

“We’ve had a prolonged heat wave going on in Mexico, Texas … Since it’s been going on for so long, it’s just been able to build and build and build that heat. Like Death Valley was 128, 129 (degrees) Sunday,” Danielson said. “… And that’s what we experienced (Monday).”

Though temperatures will cool off this week compared to Monday’s heat spike thanks to a low pressure system that is expected to push the heat wave south toward the U.S.-Mexico border, the high pressure system is expected to heat up Summit County in the near future. 

“By early next week, we will start to warm up pretty well again,” Danielson said. “Maybe Monday, Tuesday, Wednesday next week — you might start to see temperatures in the mid-80s to upper-80s again.”