The national Saudi weather agency issued a red warning, the highest level, on Tuesday for the western coastal area along the Red Sea, where cities such as Jeddah, Mecca, and Medina are located, reports the Anatolia news agency.
Milder weather warnings also apply to the capital Riyadh, which is located further east, closer to the Persian Gulf.
"In wet conditions, lamp posts and other electrical equipment can become electrified", remind Mecca's regional authorities the residents.
The dictatorship's national news agency SPA writes that both rain and hail, as well as strong winds, are expected to continue in the country's southern half for the rest of the week. The risk of further flooding is assessed as high.
Despite the desert climate, it is not entirely unusual for flooding to occur in Saudi Arabia. According to the World Bank's climate change theme site, the country has been hit by flooding at least ten times since the turn of the millennium.