Colorado's Worst Ozone Summer and the Lucas Fire's Containment — September 23, 2026

A mixed day of news: one region tallying up a rough ozone season now that summer is over, another watching a wildfire finally close out, and a third still under an active air quality alert.

Metro Denver's ozone season among the worst in decades

Metro Denver and the northern Front Range logged 66 days this summer when ozone pollution exceeded federal standards, according to the Regional Air Quality Council, a state air-quality agency, as the Denver Post reports. That ties 2012 for the second-worst count in the 30 years the council has tracked data, behind only 2021's 67 days.

Wildfire smoke contributed but wasn't the main driver, the council's director said, calling it "a homegrown problem that smoke only exacerbates." The extended stretch of bad air could push the region toward a tougher federal non-attainment designation, which would mean higher fees for industrial polluters.

Lucas Fire reaches full containment in Northern California

Crews reached full containment Sunday on the Lucas Fire, a lightning-sparked blaze that burned 4,128 acres along the Mendocino–Lake County line, as the Santa Rosa Press Democrat reports. It became the largest fire this year in Cal Fire's busy Sonoma-Napa-Lake unit.

No homes were lost, though three structures burned, including equipment at an emergency communications radio site. Crews are now doing repair work — clearing debris and smoothing out fire lines — to limit the fire's lasting environmental impact.

North Texas under an ozone alert as a dry summer drags on

The National Weather Service issued an Air Quality Alert for most of North Texas through 6 p.m. Wednesday, warning that atmospheric conditions favored high ozone levels, as FOX 4 News reports. Dallas-Fort Worth highs are running in the low-to-mid 90s.

The NWS says 2026 is tied for the second-driest summer on record at DFW Airport, with 67 days without measurable rain, and tied for fifth-hottest with 52 days above 100 degrees. If ozone alerts like this one are in your area, it's a reasonable day to keep strenuous outdoor activity light.

Cattle join the fire line on Colorado's Gold Mountain Fire

On the Gold Mountain Fire in western Colorado, ranchers turned loose 350 GPS-collared cattle to graze down grass and brush along a three-mile stretch of the Big Cimarron River, helping thin the fuel near an indirect fire line, as the Aspen Daily News reports. U.S. Forest Service range staff say the collars, tracked by an app, let them move the herd without the fencing and staffing grazing used to require.

Fire officials said the cattle offered a safer alternative to a hazardous back burn, and were on standby to be pulled if conditions on the 87%-contained fire changed.

Sources

• Colorado's 2026 ozone pollution was among the worst in 30 years — The Denver Post
• Crews reach full containment of lightning-sparked Lucas Fire near border of Mendocino and Lake counties — Santa Rosa Press Democrat
• Dallas Weather: Rain chances return to the forecast for Wednesday — FOX 4 News
• Marston: Contain a wildfire? Call in the cows — Aspen Daily News

Canairy aggregates publicly reported air-quality and wildfire news and summarizes it in plain English, with links to the original sources. This is educational information, not medical or emergency advice. In a wildfire or air-quality emergency, follow guidance from local authorities.