Fierce storms closed schools Wednesday in Saudi Arabia's Mecca region, home to Islam's holiest site, the Grand Mosque, which was lashed by heavy rains and wind overnight, witnesses said.

As pilgrims tried to circumambulate the Kaaba, the giant black cube towards which all Muslims pray, a bolt of lightning struck the iconic Fairmont Makkah Clock Royal Tower hotel, illuminating the night sky late Tuesday.

The storm brought gale force winds exceeding 80 kilometres (50 miles) per hour, Hussein al-Qahtani, spokesman for the National Centre for Meteorology, told AFP.

The conditions were similar to a 2015 storm that felled a crane at the Grand Mosque, killing more than 100 people and injuring hundreds more, Qahtani said.

No casualties were reported in Tuesday's storm.

Mecca resident Abu Mayyada told AFP he was out buying cigarettes and petrol when "everything went black in front of me" as the worst of the storm hit.

"Suddenly I lost control over the vehicle. I couldn't see anything so I started listening to the Koran on the radio. I didn't understand what was happening," he said.

The Mecca neighbourhood of Al-Kakkiyah recorded 45 millimetres (1.8 inches) of rain within 24 hours, the meteorology centre shared in a post on X, formerly known as Twitter.

Footage shared with AFP by Mecca residents showed pilgrims outside the Grand Mosque who were toppled over by the wind, which also sent crowd barriers sliding across the rain-slicked floor.

"The scene was very scary," said Mecca resident Mohammed, who was grocery shopping at the height of the storm.

"Everything happened within a few minutes, when it started raining in a crazy way."

Another resident, Yusuf, said August usually brought strong winds to Mecca but that Tuesday's storm was "the worst" he could remember.

The residents gave only their first names for fear of reprisals.

Flash flooding had mostly dissipated by Wednesday morning, said the residents, who gave only their first names for fear of reprisals.

Nevertheless the Mecca regional government said on X that schools would be closed in parts of Mecca, with classes conducted on an e-learning platform, "in the interest of everyone's safety".

The meteorology centre warned of further storms on Wednesday bringing rain, wind and thunder to the Mecca region and elsewhere in western Saudi Arabia.