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.
AQI 65 from 4 PurpleAir sensors · Holding steady · data from PurpleAir
As of , the air quality in Sitka, Alaska is AQI 65 — Moderate and holding steady — with PM2.5 at 16.5 µg/m³, the median of 4 live PurpleAir sensors reading 59 to 68. Canairy's verdict: Mostly clear.
For scale, that PM2.5 reading is about 1.1 times the World Health Organization's 24-hour guideline of 15 µg/m³. The WHO figure is a daily average and this is a live reading, so read it as a sense of magnitude rather than a formal exceedance — a brief spike and a bad day are not the same thing. More on the WHO guidelines
Pollen today in Sitka: grass pollen is the strongest of the three at a none level, from Google's pollen forecast. Canairy shows the tree, grass and weed forecast beside the air reading on every plan, including the free one.
Free to download · Live data from PurpleAir & public monitors
Live PurpleAir sensor map for Sitka and Angoon, Kake, Hoonah, Juneau. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Sitka
The sensors Canairy reads in Sitka agree right now — all 4 sit in the Moderate band, a 9-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 0.7 mi ENE | 59 | Moderate |
| 0.7 mi NW | 63 | Moderate |
| 1.9 mi ESE | 68 | Moderate |
| 4.8 mi NNW | 66 | Moderate |
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.
What Canairy does for Sitka
A clear verdict
Not just a number — a plain-English call for Sitka: open the windows, or keep them shut.
Smoke alerts
A push or text the moment the air crosses your threshold — and again when it clears.
A heads-up before it's bad
Trend alerts catch the air turning, so you can close up the house before the smoke settles in.
Every place you care about
Home, work, the kids' school — across Sitka or across the country, on one screen.
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?
As of September 14, 2026 at 6:39 AM PDT, the air quality in Sitka, Alaska is AQI 65 — Moderate — with PM2.5 at 16.5 µg/m³, the median of 4 live PurpleAir sensors. Sensitive groups may want to take it slower outside.
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 the AQI numbers mean
| AQI | Category | What it means for you |
|---|---|---|
| 0–50 | Good | Open the windows. Great for outdoor activity. |
| 51–100 | Moderate | Sensitive groups may want to take it slower outside. |
| 101–150 | Unhealthy for Sensitive Groups | Kids, elderly, and respiratory conditions stay closer to home. |
| 151–200 | Unhealthy | Skip outdoor exercise. Close windows. |
| 201–300 | Very Unhealthy | Limit time outside. N95 if you must go. |
| 301+ | Hazardous | Health emergency. Stay inside, run filtration if you have it. |
Canairy lets you tighten these bands if you’re more sensitive than the EPA default, so an alert can fire before the official category changes. How to read the Air Quality Index
Where these readings come from
The AQI at the top of this page is the median of the 4 curated PurpleAir sensors Canairy tracks in and around Sitka, with outliers set aside so that one sensor brought indoors — or parked beside a barbecue — cannot set the number for a whole city. Every sensor behind it is listed above with its distance and bearing from the city center. There is no black box here.
In the app, a place you save resolves the same way first. When no neighborhood sensor is reporting it falls back to the nearest EPA AirNow monitor, and anything modeled rather than measured is labelled a regional estimate rather than passed off as a sensor reading. How low-cost sensors compare to regulatory monitors
About Canairy
Canairy is free to download. The free plan covers one saved place with live readings, a plain-English verdict, and push alerts when the air crosses a threshold you choose. Paid plans add more places, faster refreshes, and SMS alerts. It is built by two parents in Sonoma County, California, who got tired of guessing whether it was safe to send the kids outside. Why we built it
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Air quality near Sitka
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