Air Quality in Sitka, Alaska — Live

Live readings from sensors around Sitka Sound — with free alerts if wildfire smoke or a summer haze rolls in.

Live Sitka AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Sitka and Angoon, Kake, Hoonah, Juneau.

Sitka gets some of the cleanest air of any American city most of the year — the same Pacific storms that dump 130 to 200 inches of rain onto Baranof Island every year also wash fine particles out of the sky before they can build up. The state's own air monitor here, installed on Katlian Street in 2024, has logged readings mostly in the "Good" range season after season. The exceptions are a run of days most Augusts when wildfire smoke drifting down from fires in Canada or Alaska's interior pushes the numbers into "Moderate" territory, and the odd stretch of cruise season when ship traffic in Sitka Sound adds its own exhaust to the mix.

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 Sitka's air is usually excellent

Sitka sits on the outer, ocean-facing coast of Baranof Island in the Alexander Archipelago, with nothing between it and the open North Pacific but Sitka Sound. That exposure brings a nonstop parade of storm systems — an average of 130 to 200 inches of rain a year, among the wettest weather in North America — and the same wind and rain that make Sitka famously soggy also scrub the air clean. There's no month here with an average temperature below freezing, and no dry season that lets particles build up the way they do in interior Alaska or the Lower 48.

The state's own numbers back this up. The Department of Environmental Conservation installed a QuantAQ air sensor at 456 Katlian Street in March 2024, part of its Community-Based Air Monitoring Project with the Sitka Tribe of Alaska, tracking PM2.5, ozone, and nitrogen oxides around the clock. Through the 2024 season the readings stayed mostly in the "Good" range on the Air Quality Index, with only brief "Moderate" spells and a median 24-hour PM2.5 reading of about 3.5 micrograms per cubic meter.

What actually moves the needle: August smoke and cruise season

When Sitka's air quality does dip, the state's own monitoring data points to a specific cause: smoke that has traveled hundreds of miles. The 2024 season's data report found August carried the highest PM2.5 concentrations of the whole April-to-September stretch, and attributed it to smoke carried down from wildfires burning in Canada — not anything burning nearby. Southeast Alaska's rainforest is simply too wet to carry a fire season the way the interior does, so almost all the smoke Sitka sees has arrived from somewhere else.

That same window overlaps with cruise season, which runs roughly May through September and can bring more than a dozen large ships into Sitka Sound in a single week. A National Park Service study measured elevated nitrogen and sulfur deposition at Sitka National Historical Park and linked it to marine engine exhaust — the nitrogen oxides, sulfur oxides, and fine particles that come from burning heavy marine fuel. Sitka is now part of a Pacific Northwest-to-Alaska "green corridor" project with Juneau, Haines, and Skagway looking at lower-emission cruising, but for now, a still August afternoon with several ships in port is one of the only times Sitka's air quality reliably moves off "Good."

The volcano next door that Sitka keeps an eye on

Fifteen miles west of downtown, across Sitka Sound, sits Mount Edgecumbe — a dormant stratovolcano on Kruzof Island that hasn't erupted in roughly 800 years. That changed from a historical curiosity to something scientists actively watch in August 2018, when the ground beneath it started rising, eventually climbing more than 10 inches by 2022. The Alaska Volcano Observatory's modeling points to new magma moving in several miles underground, and a four-station monitoring network installed in 2023 now catches roughly one small earthquake a day in the area.

None of this has translated into ashfall or any current air quality impact — gas samples collected near the volcano in 2023 didn't even detect volcanic gases, and AVO's own assessment is that an eruption isn't imminent. But it's part of why Sitka pays closer attention to its air than a place with an equally clean track record might: between an active volcano being monitored a ferry ride away and a state sensor already logging readings downtown, keeping an eye on the numbers is just part of living here. Canairy adds the sensors on the ground to that picture, in plain English.

Sitka air quality FAQ

What is the air quality in Sitka right now?

This page shows the current AQI for Sitka, built from PurpleAir sensors and nearby government monitoring data, updated continuously. The map below shows every live sensor near Sitka Sound, so you can check the reading closest to your own neighborhood.

Why does Sitka's air quality dip in August?

Alaska's own 2024 monitoring report found August carried the highest PM2.5 levels of the year in Sitka, and traced it to wildfire smoke drifting down from fires burning in Canada, not anything local. Southeast Alaska's rainforest climate rarely supports its own wildfires, so almost all the smoke Sitka sees has traveled a long way to get here.

Is Mount Edgecumbe a risk to Sitka's air quality?

Not currently. Mount Edgecumbe, 15 miles west of Sitka, has shown ground deformation and small earthquakes consistent with magma moving underground since 2018, and the Alaska Volcano Observatory monitors it closely. But there's no ashfall, no volcanic gas detected in recent samples, and no sign an eruption is imminent — it's a longer-term watch item, not a day-to-day air quality factor.

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.

Where does Canairy's Sitka data come from?

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

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