Was a "mysterious fog" spotted in various areas of the world in late December 2024 something that cannot be explained? No, that's not true: There have been several regions that experienced heavy fog in late December, but there is no evidence that it is anything other than naturally occurring fog. One medical sociologist wrote in an article that social media is the "driving force behind the late 2024/early 2025 scare of a 'toxic fog' across the United States."
The claim appeared in a post (archived here) published on Instagram on December 31, 2024. The post was captioned:
☁️Mysterious fogs are showing up in multiple countries around the world.
We are ending year with another weird event I see👀
#mysteryfog #fog #uk #canada #drones
This is how the post appeared at the time of writing:
(Source: Instagram screenshot taken on Fri Jan 03 20:48:43 2025 UTC)
The narrator asserts that mysterious fogs that don't dissipate as the day goes on, have residue, and smell, have been occurring around the world in late December 2024. He says they "are going all across America," and offers video examples from other creators from Toronto, Canada and the UK to illustrate the "mysterious fog" phenomena. He suggests that the timing of the mysterious fog, coming after reports of the drone sightings in late 2024, is suspect, and suggests something may have been sprayed.
A screenshot of a 1916 patent to make artificial clouds (archived here) and another screenshot of the DuckDuckGo AI assist result for "Operation Popeye" (archived here) a classified U.S. military cloud-seeding operation during the Vietnam War, are included in the video. The narrator says this shows that weather can be weaponized. He does not make a case that any of the recent heavy fog weather events are artificial or have been weaponized or provide any conflicting weather data to support the conspiracy premise.
The scope of this fact check does not extend to the widespread reports of drones in late 2024.
The U.S. National Weather Service website has a page on fog safety (archived here) which includes a "Fog Resources" overview describing several types or fog and the terrain and weather conditions which cause fog to form. One type, radiation fog, is most prevalent in fall and winter:
Radiation fog is a very common type of fog throughout the United States. It is most prevalent during the fall and winter. It forms overnight as the air near the ground cools and stabilizes. When this cooling causes the air to reach saturation, fog will form. Fog will first form at or near the surface, thickening as the air continues to cool. The layer of fog will also deepen overnight as the air above the initial fog layer also cools. As this air cools, the fog will extend upward. The most favored areas for fog development are sheltered valleys where there is little to no wind and locations near bodies of water.
Lead Stories reached out for comment to the Canadian weather service -- Environment and Climate Change Canada. In a January 3, 2025, email, media relations spokesperson Samantha Bayard wrote:
Fog occurs naturally when water vapour condenses at ground level. Some types of fog, such as when warm moist air flows over a cold surface in the winter, does not dissipate during the day. Environment and Climate Change Canada (ECCC) is unaware of any abnormalities in any recent fog events in Canada.
When weather phenomena seem unusual there is a risk that myths and disinformation may occur on social media and elsewhere online. Its best to get your information right from the experts.
Lead Stories also reached out on January 3, 2025, to the weather service in the UK -- Met Office. They were unable to respond due to the demands of forecasting the coming cold weather and snow. An advanced search (archived here) of the Met Office account on X showed posts (pictured below) from December 28, 2024 featured quite a bit of fog in the forecast.
(Source: X screenshot taken on Mon Jan 06 22:43:44 2025 UTC)
A Google search for the term "mysterious fog" with results limited to December, 2024, (archived here) found reports from media outlets about how, on the heels of the drone sightings, there was a surge of social media reports about experiences with a purportedly mysterious fog. Some people are claiming they became sick after exposure, others post video filmed at night showing visible water droplets or ice crystals -- insisting this this is not normal -- it is normal. The reporting from outlets such as Daily Mail (archived here), New York Post (archived here) and Express U.S. (archived here) is about the phenomenon of social media posts and lacks expert scientific interpretation of local weather data, air quality testing or public health warnings.
Standing apart from the other articles is one January 4, 2025, article from Psychology Today (archived here) titled, "Mystery Fog Sparks Fear Across America -- The psychology behind the strange fog unsettling Americans." The article was written by Robert Bartholomew, who holds a Ph.D. in sociology and who is described in his bio as a medical sociologist.
Three bullet points top the article:
- Social media is the driving force behind the recent scare of a "toxic fog" across the United States.
- Reports of a mysterious fog sickening Americans reflect prevailing fears in our information age.
- The fog panic has its roots in the selective nature of perception.
Additional Lead Stories fact checks on claims about the widespread sightings of drones can be found here.
