At least three people died and flights were delayed during heavy rain that fell on Saudi Arabia Tuesday, officials said as the desert nation braced for a cool snap.

Two people in the Red Sea city of Jeddah were electrocuted, and an 11-year-old boy drowned in Yanbu further north, the civil defence agency said.

Jeddah's King Abdulaziz International Airport said eight domestic flights were delayed "due to the rainy weather conditions in Jeddah".

One international flight was diverted to Medina, it added in a statement, without giving more details.

"Air traffic is now back to normal," the airport said.

Some streets in Jeddah, the kingdom's second-largest city, were flooded.

A picture posted by the civil defence agency showed water over the wheels of cars in one Jeddah location, but elsewhere it covered only the feet of firefighters.

The government urged Jeddah residents to stay home, and reportedly gave children there a day off school on Tuesday.

"The next few hours will see more moderate rains in Jeddah and its northern areas," said Hussein al-Qahtani, a weather department spokesman.

Even heavier rains fell in the northwestern city of Tabuk, near Jordan, where 46 millimetres (1.8 inches) were recorded since Monday, Qahtani said.

Following cool winds, moderate to heavy rains would on Wednesday move east to the Riyadh region and other areas, he told Al-Ekhbaria television news channel.

Floods killed 123 people in Jeddah in 2009, and about 10 people two years later.