Fair weather always seems to play hard-to-get on weekends. During the work week, we toil under buzzing fluorescent tubes, teased by the orgy of photons just beyond the windows. But when the weekend arrives, too often it seems to bring gray, drooling skies with it.

Well, it’s not our imaginations, it seems. A 1998 study shows that it is significantly more likely to rain on a weekend than a weekday. To make matters worse, it appears to be OUR fault, because it is likely due to the emissions from our internal-combustion conveyances. Stupid climate karma.

From the article:

An analysis of Eastern Seaboard weather shows it really does rain more frequently on the weekend than during the week. Saturdays receive an average of 22% more precipitation than Mondays, climatologists at Arizona State University report.What’s more, the clouds are, to some extent, the product of the very jobs people are trying to escape.

The ASU researchers, who analyzed weather data dating back to 1946, say weekend storms probably are enhanced by air pollution spewed by millions of cars and trucks during weekday commutes.

The pollution generates tons of tiny airborne particles, called aerosols, that become the microscopic seeds around which rain drops develop.

Similarly, a study in 2017 showed that lightning strikes are approximately twice as common over oceangoing shipping routes compared to the general atmosphere. This is owing to the aerosols emitted by container ships, which can freeze high in the atmosphere and jostle against one another to build up electric charge. This effect is known as “aerosol convective invigoration.”