Eighteen dead as floods deluge Saudi Arabia
The toll covered much of the country, with deaths reported in Riyadh, Hail, Mecca, Medina, Al-Baha, Asir, Najran and Jizan.
Response teams rescued 915 others, the agency reported.
Two people died in the southwestern Jizan region - near the Yemeni border - where the region's mountainous terrain caused severe flooding.
One person died and 27 people were wounded 300km [180 miles] away in Al-Baha, due to road accidents caused by heavy rain.
The rare storm began on Tuesday and caused widespread chaos across the country.
Traffic reportedly backed up for miles along several of the capital's main thoroughfares and many vehicles broke down after the unexpected deluge overwhelmed Riyadh's streets.
An emergency plan to deal with the flooding came into effect, said spokesman for the municipal council Mohammed al-Shwayman.
Residents were urged not to gather in affected areas "for the sake of taking pictures and videos, putting their lives at risk", Shwayman added.
But official warnings to stay far from afflicted areas did not stop defiant residents from sharing images of the floods on social media.
Severe rain is rare in the kingdom which generally enjoys an all-year hot climate.