A bizarre new conspiracy theory, dubbed “Fogvid-24,” is spreading across social media, with users claiming that the thick fog currently engulfing parts of the United States is a man-made chemical weapon.
As 2025 began, several regions in the U.S. were blanketed by dense fog, which some claim has caused breathing issues, fatigue, and strange chemical odours.
Viral videos on X (formerly Twitter) and TikTok show people shining flashlights into the fog at night, revealing what they describe as “enormous particles.”
Many users believe the fog is filled with chemicals or biological agents deliberately released by the government. Some have linked it to recent drone sightings, while others claim a rise in chemtrails just before the fog appeared.
“Described as a thick, lingering blanket, the fog has left people sick—many experiencing sudden cold or flu-like symptoms after only brief exposure,” one viral post read.
The scientific explanation
Despite the online hysteria, scientists have a logical explanation for these claims.
Fog is simply a cloud of water droplets or tiny ice crystals forming near the Earth’s surface when humidity reaches its dew point. This explains why particles appear larger when illuminated by a strong light.
Fog absorbs pollutants in the air, which can cause a sulfur-like smell or mild irritation—especially in highly polluted areas.
Breathing issues and sore throats can result from fog’s high humidity and ice crystals, which may irritate the respiratory system.