Air Quality in Juneau, Alaska — Live

Live readings from PurpleAir sensors across Juneau — with free alerts when winter wood smoke settles into the valley.

Live Juneau AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Juneau and Douglas, Mendenhall Valley, Auke Bay, Lemon Creek.

Juneau's air is clean for most of the year — this is a temperate rainforest capital wedged between the Gastineau Channel and the Juneau Icefield, and the marine wind off the water usually keeps things moving. The real story is winter: on cold, still nights the Mendenhall Valley acts like a bowl, trapping wood smoke from home heating close to the ground until the city itself has to step in. It happened again as recently as December 2025, when an extreme cold snap led the City and Borough of Juneau to declare an air emergency and briefly ban fireplace and wood-stove burning valley-wide.

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.

Why Juneau can legally ban your fireplace

Juneau is unusual among Alaska communities in having a standing legal tool for its worst wood-smoke days. Under CBJ Ordinance 2008-28, the city runs a Woodsmoke Control Program each year from October 1 through April 30, watching hourly fine-particulate readings from the Alaska DEC's Floyd Dryden monitoring station in the Mendenhall Valley. When enough consecutive readings show unhealthy particulate levels, the city can declare an air emergency, and under that ordinance every wood stove and fireplace in the valley has to go cold until the emergency is lifted — pellet stoves and certified masonry heaters are the only exceptions.

The most recent example came on December 20, 2025, when the city called an air emergency in the Mendenhall Valley in the middle of a brutal cold snap, then lifted it a day later once wind picked up and cleared the particulates out. CBJ's own announcement acknowledged the timing looked backwards — banning wood heat during a cold snap — but the coldest, stillest nights are exactly when smoke has nowhere to go. The city tracks and warns residents through a Woodsmoke Hotline, text alerts, and burn-ban signs posted around the valley.

The valley bowl versus the open channel

The air-quality problem is really a Mendenhall Valley problem, not a downtown one. The valley — stretching from the airport north toward Mendenhall Glacier and west to Auke Lake — is ringed by mountains that block the wind on calm winter nights, so a warm-air lid settles over the cold air below and holds wood smoke at ground level for hours or days. Downtown Juneau and Douglas, across the Gastineau Channel, sit more directly exposed to airflow off the water and don't trap smoke the same way, which is why a single citywide number can miss what a Mendenhall Valley household is actually breathing.

That divide is also why Juneau leans so heavily on ground-truth monitoring rather than assumption: the Floyd Dryden station, run jointly by Alaska DEC and NOAA's Juneau Forecast Office, exists specifically because the valley's air can be dramatically worse than the rest of the borough on the same night. Reading sensors placed near where people actually live, rather than one number for a geographically split-up city, is the only way to know which side of that divide you're on.

Wildfire smoke is rare here, but not unheard of

Southeast Alaska's coastal, rainy climate mostly spares Juneau the wildfire-smoke seasons that define much of the West. But that changed briefly in July 2023, when intensifying wildfires in British Columbia pushed the Alaska Division of Air Quality to issue the region's first-ever wildfire smoke advisory, warning that conditions could range from good to unhealthy depending on wind direction. National Weather Service meteorologist Andrew Park described what actually showed up in Juneau as 'a thin haze — it's way up in the atmosphere and it's not really noticeable,' with the advisory noting that any smoke would tend to settle in the mountains and drain into coastal communities like Juneau overnight and in the early morning.

It was a mild event as these things go, but it was also new: Southeast Alaska had not needed that kind of advisory before 2023. With Canadian fire seasons increasingly reaching further each summer, it's a scenario worth having a sensor reading for rather than judging by eye, especially since any smoke that does arrive tends to show up overnight rather than during the obviously smoky afternoons that West Coast residents are used to watching for.

Juneau air quality FAQ

What is the air quality in Juneau right now?

This page shows the current AQI for Juneau, 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, whether that's downtown or the Mendenhall Valley.

Why does Juneau sometimes ban wood stoves in the winter?

Under CBJ Ordinance 2008-28, the City and Borough of Juneau can declare an air emergency when hourly fine-particulate readings from the Mendenhall Valley's Floyd Dryden monitoring station show sustained unhealthy levels, usually on cold, calm nights when a temperature inversion traps wood smoke close to the ground. During an emergency, fireplaces and wood stoves in the valley must stay unlit until conditions improve — the city called one as recently as December 2025.

Does wildfire smoke ever reach Juneau?

Rarely, and usually only as thin, high-altitude haze rather than the thick smoke seen further south. In July 2023, intensifying wildfires in British Columbia prompted Southeast Alaska's first-ever wildfire smoke advisory, with any smoke tending to settle in the mountains and drain into coastal communities like Juneau overnight.

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 Juneau data come from?

Readings come from PurpleAir's network of laser particle sensors across Juneau 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.