The Colorado Department of Public Health & Environment issued an Air Quality Health Advisory for Summit County on Monday, July 12, warning that wildfire smoke drifting in from across the Western U.S. could impact those sensitive to air pollution.

The advisory went into effect at 7 a.m. and is expected to last until about 9 a.m. Tuesday, July 13, according to the state’s public health department. The current advisory stretches across a wide swath of western, northern and central Colorado as much of the state continues to deal with the lingering haze.

“Right now, it’s not just Summit County; it’s almost the entire state seeing plenty of smoke,” National Weather Service meteorologist Zach Hiris said. “And it’s from a variety of wildfires anywhere from Oregon to California, with probably a couple contributing fires in Colorado, as well. So it’s a lot of smoke from a lot of different sources at the moment.”

According to the health advisory, the northern Routt County area has been impacted the most due to its proximity to the Morgan Creek Fire burning in the Routt National Forest. Smoke from the 3,414-acre blaze, about 5.3 square miles, is expected to push downwind to the southeast throughout the day into mountain valleys like the Interstate 70 corridor in Summit County.

Smoke from out-of-state wildfires will bring hazy skies and elevated levels of fine particulates statewide, according to the advisory.

The state public health department is recommending that individuals stay inside and limit outdoor activity if the smoke becomes too thick in the area, especially for individuals dealing with heart disease or respiratory illnesses, and very young children or older adults.

Community members should consider smoke levels to be unhealthy if visibility is reduced to less than 5 miles. For reference, individuals in downtown Dillon or Frisco should be able to see Buffalo Mountain, and those in Breckenridge should be able to see mountain tops above the ski area, according to Summit County officials.

According to air quality index readings as of 11 a.m. Monday in Aspen, the state public health department’s nearest monitoring site, the air quality was good to moderate, with readings between 39 and 100 on a scale from zero to 500. The readings are taken from a 24-hour average. If the index reading reaches 101, the air quality is considered unhealthy for sensitive groups. If it reaches 151, the air quality is considered unhealthy for the general public, according to AirNow, a government partnership between the U.S. Environmental Protection Agency, the National Oceanic and Atmospheric Administration and others.

Dan Hendershott, Summit County’s environmental health manager, said air quality sensors were placed across the northwest portion of the state as part of a grant project a few years ago. While not the same quality as the monitors in Aspen, the sensors do provide readings on the air quality index on a 10-minute average.

According to sensor data collected by PurpleAir.com, the air quality in Summit County is currently unhealthy for sensitive groups, with readings between 91 and 133.

“It’s a tough balance because we’re big on outdoor activity, both in terms of our lifestyle here in the mountains but also in terms of promoting an active lifestyle for health,” Hendershott said. “We don’t want to be couch potatoes and promote being sedentary people. We want to be outdoors and active, but especially if you’re sensitive to smoke, you might want to rethink that.

“If you were thinking about hiking a 14er today, maybe just go for a couple mile walk with your dog. It’s really that prolonged, vigorous activity that seems to cause more trouble for people. We’re usually not telling people to stay home unless it’s really bad. But just back off from the very rigorous activity.”

Hendershott said those recreating outdoors should also drink plenty of fluid. He also recommended that individuals worried about smoke in their homes create a clean air room by closing the windows and running an air filtering unit such as a HEPA filter or a cheaper, do-it-yourself fan filter system.

Hiris said it’s difficult to pinpoint exactly where the bulk of the haze is coming from, as it’s likely an amalgam of smoke from wildfires throughout the Western U.S. He continued to say that the smoke lingering in the area is as much a result of current weather patterns as the intensity of fire behavior in the West.

“We’re kind of in this pattern with a pretty strong high-pressure system over the area,” Hiris said. “When that happens, you just have these kind of slow-drifting winds. There are plenty of dry, windy conditions out further west where the fires are. But for here, we’re just under this ridge of high pressure, and we’ll just have these light winds blowing the smoke from west to east into Colorado.”

While fires are already burning throughout Colorado and the West, it’s still relatively early in the wildfire season, which means Summit County residents and visitors might have to get used to murky skies over our peaks in the coming months.

“Fires are going to be on the West Coast for probably the rest of the summer and into the fall,” Hiris said. “So it’s really going to depend more on how active those fires are from day to day and what the overall upper-level wind pattern looks like for us. If we’re getting these kinds of light westerly-to-northwesterly winds, we’re going to have plenty of smoke and haze. But if we get winds out of the south and southeast, typically that smoke is not going to stay. It depends a lot on how weather systems evolve from day to day. It’s not going to be an everyday thing, but it’s probably going to be a common sight as we go through the next couple months.”

Summit County remains in Stage 1 fire restrictions, which prohibit all open fires and fireworks. The fire danger level in Summit County remains moderate.