Denver just logged its second Action Day alert in two weeks, and this one is not the ozone haze we wrote about last time. It is wildfire smoke, thick enough to push particulate levels into the Unhealthy for Sensitive Groups range across the northern Front Range. The same week, Xcel Energy put a real number on how much more Coloradans will pay to heat and light their homes this year, and NOAA has still not backed off its strong El Nino call for the winter ahead. None of that is fireplace news on its face. All three land on the same chimney: what you burn, what it costs, and whether the flue is ready before the first cold front drops off the Divide.
Metro Denver's second Action Day in two weeks, and this one is smoke
The Colorado Department of Public Health and Environment and the Regional Air Quality Council issued a Multiple Pollutants Action Day Alert at 4 p.m. Monday, August 3, for the Front Range Urban Corridor, from Douglas County north through Larimer and Weld, covering Denver, Boulder, Fort Collins and Greeley. Unlike the ozone-only alert two weeks ago, this one is being driven by wildfire smoke moving into the region:
"Increasing wildfire smoke will result in fine particulate concentrations reaching the Unhealthy for Sensitive Groups category throughout the northern Front Range region. Additionally, ozone could reach the Unhealthy for Sensitive Groups category Tuesday afternoon and evening."
Source: CDPHE and Regional Air Quality Council, Front Range Action Day Alert, August 3, 2026
The alert runs until at least 4 p.m. Tuesday, August 4. You can check the live status any time at colorado.gov/airquality. Open burning is prohibited while it is active, which in August means the fire pit, not your fireplace. But it is a preview of the machinery that governs indoor wood-burning starting November 1, when the same Action Day system flips from outdoor to indoor burning restrictions across the seven metro counties for anyone below 7,000 feet running an uncertified device. We cover exactly who is affected in our guide to Colorado chimney laws and regulations. If you are tired of watching the advisory page every time the wind shifts, a gas insert sidesteps the restriction entirely.
NOAA still has not backed off a strong El Nino winter
The Climate Prediction Center's most recent ENSO Diagnostic Discussion, issued July 9, kept the El Nino Advisory active and put real numbers behind it: a 97 percent chance El Nino persists through early spring 2027, and an 81 percent chance it reaches very strong intensity between October and December. Those are the same figures we flagged two weeks ago, and the fact that CPC has had no reason to walk them back since is itself the update. Nothing about this pattern is cooling off.
What this means for your home: a strong El Nino tends to favor an active southern storm track, and when that lines up with Front Range upslope flow, the result is the wet, heavy, multi-day snow that soaks masonry rather than the light, dry powder that blows off it. For a chimney, water is the whole story:
- Freeze-thaw. Brick that gets wet and then freezes overnight is how Colorado spalls mortar joints, and it happens more in wet winters than cold, dry ones.
- Crown and cap. A hairline crack in the crown is invisible in August and a leak by January. A rusted or missing chimney cap lets snowmelt run straight down the flue.
- Draft. Cold, damp air sitting in an exterior chimney is the usual reason a fire smokes back into the room on the first hard-freeze night of the season.
- Timing. The week after the season's first real storm is the worst week to try to book anyone in this trade. Get a chimney inspection in Denver on the calendar while the weather is still dry.
The heating math just got more expensive, on both gas and electric
Two separate Xcel Energy rate cases moved in the last few weeks, and together they change the calculation homeowners are making about the fireplace this winter. On the electric side, Xcel, Public Utilities Commission staff and other parties proposed a $225 million settlement that would raise the average residential bill by roughly $6 a month, which the state's utility consumer advocate has called the largest electric rate increase in Colorado history. On the gas side, PSCo (Xcel's Colorado subsidiary) filed a separate settlement on July 13 covering a $123 million revenue increase, described in its own SEC filing as a 7.5 percent total increase, with a Commission decision expected in the fourth quarter. Between the two, homeowners heating and lighting their homes with Xcel service are looking at real, stacked increases on top of what they already pay.
What this means for your home: a higher utility bill makes the fireplace look like a better heat source right when people are most tempted to lean on a flue that has not been swept in years. That is a fine instinct, but only with a clean, lined, properly drafting chimney behind it. A dirty or damaged flue is not a way to save money, it is a deferred bill with worse timing. A sweep and cleaning costs less than a single month of what these rate cases are arguing over, and it is the difference between a wood stove or gas insert that actually cuts your bill and one that just adds risk.
What we would do before the next edition
- Bookmark colorado.gov/airquality and check it before you burn anything outdoors this month. A second Action Day in two weeks means a third is not unlikely.
- Get eyes on the crown and cap before the first storm. Cracked crown, rusted cap and missing spark arrestor are the three problems that are cheap to fix in August and expensive to fix in February.
- Book your inspection now. A wet, El Nino-leaning winter means everyone calls the week after the first storm, all at once.
- If you are planning to burn more this winter to offset a higher electric or gas bill, budget for a sweep first. A clean flue is what makes that plan actually save you money.
- Test the CO alarms. If wood heat is doing more work in your house this winter, that alarm is the cheapest safety device you own.
If you want a straight answer about what your chimney actually needs before winter, call us at (720) 207-9232 or reach out through our contact page. We serve Denver and the Colorado Front Range, and we will tell you when something can wait.
The Flue Report is published every two weeks by Adam Chimney Sweep, serving Denver and the Colorado Front Range. Edition 4 lands the week of August 18, 2026.
