Smoke forecast
Where the smoke over Denver was, and where the model sends it next. Scrub back 12 hours or forward 48. Every hour shown is a model estimate, not a measurement.
The scale is anchored to visibility, because that is the one reading you can take yourself without trusting a model. Distances are approximate.
Longs Peak is sharp to the northwest, about forty-five miles out, and on the best days Pikes Peak reads south at over sixty.
Longs is gone. Mount Blue Sky still marks the west, roughly thirty-five miles off, but the range behind it has gone to one grey wall.
The Front Range flattens to a silhouette. The foothills above Golden, about fifteen miles west, are the furthest thing you can still resolve.
From Sloan's Lake the downtown skyline holds two miles east, while the foothills behind it vanish entirely.
The tops of the downtown towers go. From City Park you can lose the skyline that sits three miles away.
Denver's haze has two separate causes and they get confused constantly. The Front Range produces its own summer ozone and brown cloud from traffic and industry trapped against the mountains, which is a local problem with local timing. Wildfire smoke is different: it arrives from Colorado's own western slope, from Utah and the Great Basin, and increasingly from California and the Pacific Northwest on upper-level flow that carries it a thousand miles east.
The 2020 season is the marker, when the Cameron Peak and East Troublesome fires burned close enough to drop ash on the metro. But the more common modern pattern is high smoke from somewhere else entirely, which is why the mountains disappear on days when nothing in Colorado is burning.
Denver's brown cloud is not wildfire smoke. Traffic and industry emissions get trapped against the Front Range and cook into ozone through the summer, which produces a brown-tinged haze on hot afternoons with nothing burning anywhere. It looks like smoke, it hurts to breathe like smoke, and it is a separate problem with separate timing. Smoke arrives and leaves with the wind. The brown cloud builds through the day and breaks with a front.
The verdict at the top of this page answers that for Denver specifically, and it is a smoke forecast rather than a haze forecast, which in this city is a meaningful distinction. Denver has a native brown cloud that looks like smoke and is not, so the verdict can read All clear on an afternoon when the Front Range has genuinely disappeared. The section above on what is not smoke covers the tell. Everything shown is a model estimate rather than a measurement at your address.
That is the headline answer above: the clear time, the first stretch of at least six straight hours below the Hazy threshold. Smoke and the brown cloud clear on completely different schedules, and confusing them is the standard Denver mistake. Smoke arrives and leaves with the wind, so a clear time is a wind forecast. The brown cloud builds through the day and breaks with a front, which no clear time on this page is describing.
There are two answers and the page will not pretend they are one. If it is a hot summer afternoon with no wind and a brown tinge at the horizon, that is most likely ozone off Front Range traffic and industry, trapped against the mountains, a local problem with nothing burning anywhere. If it is smoke, it has usually travelled: Colorado’s western slope, Utah and the Great Basin, or California and the Pacific Northwest on upper-level flow a thousand miles east.
Increasingly from a very long way away. The near sources are Colorado’s own western slope and the Utah and Great Basin fires; the far one, and now the more common pattern, is California and the Pacific Northwest arriving on upper-level flow. That is why the mountains disappear on days when nothing in Colorado is burning. The local exception was 2020, when Cameron Peak and East Troublesome burned close enough to drop ash on the metro.
The five-day strip above gives the day-by-day read and the timeline covers forty-eight hours hour by hour. For smoke, "better tomorrow" is a question about upper-level flow a thousand miles west, which is why the page shows where the models disagree. For the brown cloud it is a question about whether a front is coming, and that is a plain weather forecast rather than anything this page computes.
Longs Peak to the northwest is the first check at about forty-five miles, and Pikes Peak south of it at over sixty is the best-day-only test. When Longs goes but Mount Blue Sky still marks the west, something has arrived. When the Front Range flattens to a silhouette and the foothills above Golden are the furthest thing you can resolve, it is well in. And watch the colour while you do it: smoke goes grey-brown and carries a smell, the brown cloud does not.
Where Denver's smoke usually shows up first, and the places that share its air.
Utah and Great Basin smoke reaching the Front Range crosses the Salt Lake bowl first, a day or so ahead on the same westerly flow.
The northern Sierra and northern California smoke that arrives over Denver aloft passes the Truckee Meadows on its way east.
This is the corridor where the haze is not always smoke, and saying so is most of the job.
Smokeshow is for informational and educational purposes only. It is not health, medical, or safety advice. Forecasts are model estimates and can be wrong, sometimes by a lot. Descriptions of what you might smell, see, or feel are generalizations, not predictions about your body. For decisions about your health, outdoor activity, or air quality safety, rely on official sources like AirNow.gov, the National Weather Service, and your local health authorities, and talk to a medical professional about your own situation.