Unusual Smell in the Air in Chicagoland and fire departments received reports of the mysterious odor (Asal Rezaei/CBS Chicago). YouTube Tips ⓘ
In Arlington Heights there was an unusual odor that smelled like electric burning similar to a burnt ballast from a fluorescent light fixture. The odor was strong enough to consider double checking the house. The same odor was present over a mile away.
A mysterious, widespread odor, described as chemical, burning electrical, or metallic, was reported across the Chicago area, parts of Wisconsin, and Indiana on Sunday, February 8, and Monday, February 9, 2026, with some fire departments getting calls to investigate. There were official reports or social media report from the Wisconsin border to central Illinois. Officials did not initially identify the source.
The odor, which had a variety of descriptions was reported in Arlington Heights, Algonquin, Lake in the Hills, Bloomingdale, Mount Prospect, and . In Arlington Heights, the odor was strong enough to cause concern that something might be burning. The odor was similar to a burning electrical type smell; however, some reported chemical odors, burning plastic, a rotten egg smell, a sewer smell, rubber, or a strong, bleach-like odor. At least one person described the smell like Roundout weed killer.
The Algonquin-Lake in the Hills Fire Protection District posted a message at 9:57 a.m. Sunday, February 8, 2026 that the fire agency had received multiple 911 calls regarding an unknown odor described as a chemical or burning electrical smell in the air. Reports spanning a wide area had been ongoing for approximately 12 hours overnight Saturday to early morning Sunday. Algonquin-Lake in the Hills Fire Protection District reported being aware that reported came from central Illinois through Indiana and as far north as the Wisconsin border. The source of the odor apparently was coming from a distance quite south of here, according to the Algonquin-Lake in the Hills Fire Protection District.
At this time, the source of the odor is **unknown**. We are actively monitoring the situation and coordinating with regional partners and other agencies to gather information.
If you notice this odor:
* Seek medical attention if you experience symptoms such as difficulty breathing, dizziness, nausea, or irritation
* Call 911 **only if there is an immediate emergency or life-safety concern**
While no definitive source of odor has been found, some experts speculated that a temperature inversion trapped local odors and/or odors originating from a source far south of Chicagoland in central Illinois. Normally color air is at higher altitudes, but if colder air gets trapped under an unusual warmer layer at higher elevation there is a phenomenon known as the “Lid Effect.” Cool air is more dense. Odors get concentrated because the warm layer lid prevents air from mixing vertically. I’ll combine mixture of odors from traffic, industrial emissions, woodburning, fireplaces, and natural sources like decaying leaves which have been trapped under melted. Skunks are another source of odor that can combine with the mixe. Concentration of trapped air brings all these odors to a concentrated unidentified odor.
Inversions are more likely on clear, calm and cold nights, especially in winter, or during early fall. The odor can be especially concentrated in valleys or low lying areas.
The odor ends when a new weather system, such as a cold front moves into the area, or higher winds, or new daytime heating that rises on a sunny day, which breaks through the lid.
Historically, strong odor in the air has been caused by smoke from Canadian wildfires. Apparently the upper air travel of smoke and particles from Canada wildfires gives off a sort of burning plastic smell along with the burning wood smell. The AQI was as high as 250 (Very Unhealthy for All Individuals) on June 27, 2023, dues to Canadian wildfire smoke. No significant active Canada wildfires were reported Sunday, February 8, 2026.
In July 2025, Air Quality in Chicagoland was rated “Worst in the World” for the date of July 31, 2026 with AQI ratings about 177 to 196.
In January 2024 a leak from an Indiana BP oil refinery caused an odor in Chicago’s South Suburbs (CBS News – Leak from Northwest Indiana oil refinery storage tank causes odor in south suburbs)
According to EPA’s AirNow.gov, the air quality index (specifically AQI Moderate for ozone and particulate matter) was worse Tuesday, February 10, 2026 compared to Sunday, February 8, 2026 (AQI Good for ozone and particulate matter). One Wednesday, February 11, 2026, the AQI is “Moderate” at 51.
A Good rating is 0 to 50.
A Moderate reading is 51 to 100.
The first unhealthy rating is “Unhealthy for Sensitive Groups” at 101 to 150.
See also …
If the odor causes symptoms like throat or eye irritation, residents should seek medical attention, but avoid calling 911 unless it is a life-threatening emergency.
^^ MOBILE? USE VOICE MIC ^^
facebook …
Please ‘LIKE’ the ‘Arlington Cardinal Page. See all of The Cardinal Facebook fan pages at Arlingtoncardinal.com/about/facebook …
Help fund The Cardinal Arlingtoncardinal.com/sponsor
THANKS FOR READING CARDINAL NEWS
