Does it rain more frequently on the weekend?

Yes! (Along the US East Coast, at least).

Back when chaos theory was in fashion, aficionados used to talk about butterflies flapping their wings over Peking and causing cyclones in Fiji. The study of apparently innocuous events and their effect on the weather has one again come to the fore with researchers from Arizona State University (ASU) finding some interesting correlation between pollution and rainfall.

The study, published in Nature, suggests that rain is most likely to occur along the US Atlantic coast on the weekend and the weather is most likely to be better on a Monday, Tuesday or Wednesday. The most obvious culprit is the "natural" cloud-seeding effect created by the massive drift of East Coast pollution, which also follows a well defined weekly cycle. Even Atlantic hurricanes may feel the punch of the workweek, according to the study.