Why Does It Rain Less on Shabbat in Israel?

Have you ever noticed that the weather seems nicer on Shabbat, while mid-week rains are more common? New research from the Volcani Institute uncovers a surprising phenomenon: In Israel, there's more rainfall during weekdays than on Fridays and Shabbat.

The study, conducted by Dr. Uri Shatrovach and published in the scientific journal Climatic Change, analyzed data collected over seven decades from 60 different measurement stations. The result is clear: there's a weekly pattern where weekdays, especially Tuesday through Thursday, are more rainy, while Fridays and Shabbat tend to be drier.

Dr. Shatrovach explained in an interview with ynet: "We are not aware of a natural weekly precipitation cycle. Therefore, the plausible explanation is human activity—there is more traffic, more industry, and more air pollution during the weekdays. This releases tiny particles called aerosols, which help form clouds and cause rain. On weekends, this activity decreases—and so does the rainfall."

He added, "These differences provide an opportunity to understand how humans actually affect the weather. Our laboratory is the country itself—and we see a clear pattern that repeats over and over again throughout the years."

Dr. Shabtai Cohen, a former senior researcher at the Volcani Institute, also confirmed the findings to the website, noting that "an examination of atmospheric maps shows that the differences between mid-week and the weekend aren't just present in Israel, but are also seen in nearby regions of the Middle East."