Why It Rains More During the Week: The Surprising Weather Pattern Discovered in Israel

Why does it often seem that the weather is nicer on Shabbat, while rain tends to fall during the week? A new study from the Volcani Institute reveals a surprising phenomenon: in Israel, it actually rains more on weekdays than on Fridays and Saturdays.

The research, conducted by Dr. Udi Strobach and published in the scientific journal Climatic Change, analyzed data spanning seven decades from 60 different weather stations across the country. The results were clear: there is a consistent weekly pattern, with more rainfall during weekdays — especially from Tuesday to Thursday — while Fridays and Saturdays tend to be drier.

According to Dr. Shtrovach, in an interview with ynet: “We don’t know of any natural weekly cycle of rainfall. The most reasonable explanation is human activity — during weekdays there’s more traffic, more industry, and more air pollution. These release tiny particles called aerosols, which promote cloud formation and precipitation. On weekends, human activity drops, and so does the rain.”

He added: “Such differences offer a real opportunity to understand how humans directly affect the weather. The country itself serves as our laboratory, and we see a clear, repeating pattern year after year.”

Dr. Shabtai Cohen, a former senior researcher at the Volcani Institute, confirmed the findings and noted that atmospheric map analyses show the same pattern not only in Israel but also in neighboring regions across the Middle East.