Air Quality in Fort Collins, Colorado — Live

Live readings from PurpleAir sensors across Fort Collins — with free alerts when summer ozone or foothills wildfire smoke moves in.

Live Fort Collins AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Fort Collins and Loveland, Windsor, Wellington, Laporte.

Fort Collins sits right where the plains meet the Rocky Mountain foothills, and most days that geography works in the city's favor — clean air moving off the mountains, no heavy industry nearby. The exceptions are real and predictable: hot, sunny summer days build ground-level ozone across the whole northern Front Range, and the forests just west of town, up the Cache la Poudre canyon, have produced two of Colorado's largest wildfires since 2012.

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.

Fort Collins shares the Front Range's ozone problem

Larimer County, Fort Collins included, is part of the Denver Metro/North Front Range ozone nonattainment area under the EPA's 8-hour standard — the same designation that covers Denver, Boulder, and Weld counties. The Regional Air Quality Council, the multi-county body that coordinates the area's ozone response, states it plainly: ground-level ozone is Larimer County's most pressing air quality issue, and it is a warm-season problem, building on the hottest, sunniest days roughly from May through September.

Ozone doesn't come out of a smokestack — it forms when vehicle exhaust and emissions from oil and gas wells in the Denver-Julesburg Basin to the east, in Weld County, react in strong sunlight. Fort Collins sits close to 5,000 feet, where thinner air lets more UV through, so the same load of traffic and drilling emissions cooks into ozone faster than it would at sea level. RAQC runs a standing Oil & Gas Technical work group for exactly this reason — the wells feeding Colorado's Front Range corridor are a recognized part of the region's ozone math, not just the cars on I-25.

The foothills west of town have burned twice in under a decade

In June 2012, lightning sparked the High Park Fire above Buckhorn Road in the Roosevelt National Forest, directly in the mountains west of Fort Collins. It burned for three weeks, consumed 87,284 acres, and destroyed 259 homes — at the time the second-largest wildfire in Colorado history. It was a preview of what the same stretch of forest would do eight years later.

The Cameron Peak Fire ignited near Chambers Lake in August 2020 and burned for 112 days, eventually covering 208,663 acres to become the largest wildfire in Colorado history. It crept to within roughly 8 miles of Horsetooth Reservoir, and on its worst days the smoke was thick enough to block out the sun over both Fort Collins and Estes Park, with a pyrocumulonimbus cloud towering over the city. That same autumn, the East Troublesome Fire exploded across the Continental Divide toward Estes Park, so for several weeks in October 2020 Larimer County was dealing with major smoke from two directions at once.

Laporte and the Poudre Canyon are the city's smoke gateway

The Cache la Poudre River comes out of its canyon at Laporte, just northwest of Fort Collins, right where the forest meets the plains. That canyon corridor is also where High Park and Cameron Peak both burned, so when a fire is running in that country, Laporte and northwest Fort Collins tend to see and smell smoke first, before it spreads across the rest of the city.

The same downslope winds that give Fort Collins its frequent warm winter spells — Chinook-type gusts dropping off the Rockies — can also fan a fire in that canyon and, on other days, help push accumulated smoke or haze out of the area. It's the same geography working two different ways depending on the day, which is why a single citywide number is a rougher guide here than sensors placed close to where you actually live.

Fort Collins air quality FAQ

What is the air quality in Fort Collins right now?

This page shows the current AQI for Fort Collins, calculated from PurpleAir sensors across the city and updated continuously. The map below shows every live sensor, so you can check the reading closest to your own neighborhood.

Why does Fort Collins get bad ozone days in the summer?

Fort Collins and the rest of Larimer County are part of the Denver Metro/North Front Range ozone nonattainment area. Ground-level ozone forms when vehicle exhaust and emissions from Weld County oil and gas wells react in strong sunlight, and Fort Collins' near-5,000-foot elevation means more UV gets through, speeding up that reaction on hot, still days roughly between May and September.

Has wildfire smoke ever been a serious problem in Fort Collins?

Yes. The Cameron Peak Fire in 2020 — the largest wildfire in Colorado history — burned in the mountains about 8 miles from the city and blotted out the sun over Fort Collins on its worst days. The High Park Fire in 2012 burned even closer, igniting directly west of the city above Buckhorn Road. Both fires started in the forest that the Cache la Poudre River flows out of at Laporte, just northwest of town.

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.

Where does Canairy's Fort Collins data come from?

Readings come from PurpleAir's network of laser particle sensors across Fort Collins and surrounding towns, cross-referenced with government monitors and the Google Air Quality API. You can see every sensor behind your numbers on the live map - there's no black box.

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.

Get Canairy free on Google Play.