Air Quality in Kansas City, Missouri — Live

Live readings from PurpleAir sensors across Kansas City — with free alerts the moment the air turns.

Live Kansas City AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Kansas City and Overland Park, Independence, Lee's Summit, Liberty.

Kansas City's air is fine on most days and marginal on a handful, and the handful is what the region argues about. The EPA does not list Kansas City as a nonattainment area for ozone; it is a maintenance area, covering Wyandotte and Johnson counties in Kansas and Clay, Platte and Jackson counties in Missouri, which means the metro fixed an old ozone problem and now has to keep proving it stayed fixed. The 2024 season ran 172 green days, 67 yellow, six orange and no red. The 2025 season had six days over the standard, one of them red in mid-July. That is a region living within a few parts per billion of the federal line, year after year. The other thing that moves the number here arrives from a thousand miles away: on the morning of 7 September 2023 the AQI in Kansas City hit 159, a red day, on smoke from wildfires in western Canada, and was still at 112 the next morning.

Canairy watches the sensors around your home, your kids' school, and everywhere else you care about, and tells you in plain English when the air changes enough to matter.

The ozone number that decides Kansas City is decided by one monitor at a time

Compliance with the eight-hour ozone standard does not work the way most people assume. The standard is 70 parts per billion, but a single hot afternoon over that does not put the region in violation. What counts is the design value: the three-year average of the fourth-highest reading at each individual monitor. Any one monitor hitting 71 ppb on that average puts the whole metro in violation. Ozone here is measured at six monitors inside the maintenance area, with two more at Trimble and Leavenworth used for forecasting. In 2024 the Liberty monitor had four daily readings above the standard and reached its critical value, making it the one monitor in tentative violation, with a fourth-highest reading of 76 ppb; Heritage Park and Richards Gebaur both came in at 77 and Leavenworth at 78. In 2025 it was Rocky Creek's turn, with two other monitors landing right at 70.

That matters for how you read a citywide figure. The monitors that tip over are not downtown ones. Liberty, Watkins Mill and the sites out toward the northern edge of the metro sit downwind of the built-up core on a typical summer afternoon, and ozone is a pollutant that forms in the air over several hours as nitrogen oxides and volatile organic compounds cook in sunlight, so it tends to peak somewhere other than where it started. A number averaged across Kansas City can be genuinely comfortable on an afternoon when the air where you actually live is not.

The worst air Kansas City has had recently came from Canada

The summer of 2023 is the reference point. Smoke from Canadian wildfires, with more than 19 million acres burned nationally by late June, reached the Midwest repeatedly. On 28 June 2023 Kansas City was under an alert for air unhealthy for sensitive groups while the haze sat over the city. The sharper episode came in September: AQI 159 on the Thursday morning, 112 on the Friday, driven by particle pollution rather than ozone. MARC's own 2025 season recap describes 2023 as the year the region was badly impacted by Canadian wildfires and smoke that swept through in June and July.

2025 was a quieter year for smoke here, and the reason given was simply weather. Doug Norsby, MARC's air quality senior planner, put the 2025 season down to timely weather systems and wind that generally kept pollution moving out of the area, particularly in July. That is the honest shape of the smoke risk in Kansas City. There is no local fire season to speak of. What arrives is somebody else's fire, carried a long distance, and whether it settles on your street for an afternoon or blows through in an hour is a question about that day's wind rather than about the fire.

Where the pollution comes from in a river-bottom freight town

Kansas City sits on the Missouri River at its confluence with the Kansas River, at about 909 feet of elevation, which means a lot of the metro is bottom land with bluffs above it. Missouri's Department of Natural Resources lists the common sources of the ozone precursors as vehicles, power plants, industry, burning and biogenic emissions, and runs its ozone forecast season from 1 March through 31 October. Kansas City has more of the vehicle side than a metro its size would normally carry, because four Class I railroads have line-haul access here: Union Pacific, BNSF, Norfolk Southern and CPKC. Freight moving through a city is diesel traffic on both rails and roads, and diesel traffic is one of the nitrogen oxide sources that feeds the afternoon ozone reaction.

None of that produces a dramatic local pollution event, and it would be dishonest to suggest otherwise. What it produces is a region that hovers a couple of parts per billion either side of the standard and gets tipped over by a hot, still week. The useful thing on a page like this is not the metro headline; it is what the sensors nearest to the places you spend time are reading this afternoon.

Kansas City air quality FAQ

Why is there smoke in Kansas City today?

Almost always because a wildfire somewhere else is sending it here. Kansas City has no local fire season, but Canadian smoke has reached the metro repeatedly since 2023, when the AQI hit 159 on the morning of 7 September and was still at 112 the following day. Smoke you can smell, and it shows up on this page as a rise in PM2.5. If the sky is hazy but there is no smell, and it is a hot still afternoon between March and October, the more likely explanation is ozone, which is invisible and does not register on a particle sensor at all.

What is the air quality in Kansas City right now?

This page shows the live AQI for Kansas City, calculated from PurpleAir sensors around the metro and updated continuously. It is worth saving the specific places you care about rather than watching one citywide number, because the monitors that go over the standard here tend to be the outlying ones, not the downtown ones. What Liberty or the northland is reading on a summer afternoon can be meaningfully different from Waldo or the Country Club Plaza.

Why does the alert say ozone when I cannot see anything?

Because ozone is a gas, not a particle. It forms when nitrogen oxides and volatile organic compounds react in sunlight, which is why the alerts cluster on hot, sunny, low-wind days between March and October, and why they are usually issued the afternoon before rather than in response to something visible. It is also why a PM2.5 sensor cannot see it. On an ozone alert day the useful response is about exertion and timing rather than about closing windows, because ozone peaks in the afternoon and eases after sunset.

Is Kansas City's air getting better or worse?

Better over the long run, and roughly flat lately. The regional ozone trend came down after 2014 as power plant controls and cleaner vehicle engines took effect, and since then the metro has sat close to or just below the standard rather than clearly under it. The 2024 season produced six days over the standard and the 2025 season also produced six, with one monitor in tentative violation each year. Kansas City is not a city with an air quality crisis. It is a city where a handful of days each summer are genuinely worth planning around.

What AQI level is unhealthy?

Under the US EPA scale, AQI 0–50 is Good and 51–100 is Moderate. From 101 the air is Unhealthy for Sensitive Groups — kids, older adults, and people with asthma or heart conditions — and above 150 it's Unhealthy for everyone. Canairy translates these numbers into a plain-English verdict, like whether to close the windows or move a workout indoors.

Is Canairy free?

Yes. The Canairy app is free to download and includes live air quality for all your saved places, plain-English verdicts, and free push alerts when the air crosses your threshold. A paid plan adds extras like SMS text alerts.

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