People Told to Stay Indoors as Air Quality Nears ‘Very Unhealthy’ Levels

People in northeastern Montana were advised to limit their time outdoors on Wednesday as smoke from Canadian wildfires worsened the air quality to unhealthy levels.
Air quality at the Sidney and Glendive monitoring stations in northeastern Montana was unhealthy, with an air quality index of 190 and 193, respectively, according to a webpage for the Montana Department of Environmental Quality (MTDEQ). Unhealthy air quality levels occur when the AQI measures between 151 and 200.
Once air quality levels hit 201 or higher, air quality is considered “very unhealthy” and “the risk of health effects is increased for everyone,” the MTDEQ said. Hazardous air quality occurs at an AQI of 301 or higher.
The poor air quality comes as the National Weather Service (NWS) office in Glasgow, Montana, issued a dense smoke advisory, which will remain in effect until 6 p.m. local time on Wednesday. Strong winds also were present, prompting a lake wind advisory as well.
“Wildfire smoke may present impacts to health. Strong winds and rough waves on area lakes will create hazardous conditions for small craft,” the advisory said.
In a post on X (formerly Twitter), NWS Glasgow said the smoke would clear out by Wednesday evening.
“Smoke from wildfires has overtaken NE MT, and a reduction down to 1 to 3 mile visibility is currently occurring in a few locations,” the post said. “This is leading to unhealthy air quality, but the smoke will clear out with a north to south moving cold front this afternoon/evening.”
On its main webpage, NWS Glasgow advised people against burning debris and to keep their windows closed. People also are advised against burning candles because that can add to indoor pollution.
Smoke prompted meteorologists to issue air quality alerts in western Montana earlier this week, as wildfire smoke congregated in that part of the state. At that time, NWS meteorologist Luke Robinson told Newsweek that the smoke was caused by local fires, whereas the smoke in northeastern Montana migrated from Canadian fires.
As of Wednesday afternoon, most of MTDEQ’s air quality monitoring stations in western Montana reported moderate air quality levels, with the station in Hamilton reporting levels as “unhealthy for sensitive groups.”
As for the incoming cold front, NWS lead meteorologist Richard Maliawco told Newsweek that temperatures in northeastern Montana will drop 5 degrees from highs in the 70s and low 80s on Wednesday. Winds will pick up on Wednesday evening, with some winds gusting to 30 mph, and this will push the smoke out of the Glasgow forecast region, he said.
Maliawco warned that haze and smoke might return by the weekend, given the wildfires’ behavior.