The desert nation of the United Arab Emirates struggled to “dry out” on Wednesday from the heaviest rain ever recorded there, as a flood engulfed Dubai International Airport, disrupting travel through the world’s busiest airport.

State news agency WAM called Tuesday’s rain “a historic weather event” that exceeded “anything documented since the beginning of data collection in 1949.” This is before the discovery of crude oil in this energy-rich nation, then part of a British protectorate known as the States General.

Rain also fell in Bahrain, Oman, Qatar and Saudi Arabia. However, rainfall was severe across the UAE. One reason may have been “cloud seeding,” in which small government-flown airplanes fly through the clouds burning special salt flames. These eruptions can increase rainfall.

Some reports quoted meteorologists at the National Weather Service as saying they had six or seven new flights ahead of the rains.

The center did not immediately respond to questions on Wednesday, although flight tracking data analyzed by The Associated Press showed that a plane linked to the United Arab Emirates’ cloud-seeding efforts flew around the country on Sunday.

The United Arab Emirates, which relies heavily on desalination plants to provide water, does cloud seeding in part to boost its dwindling and limited groundwater.

The rains began late Monday, drenching Dubai’s sands and roads with about 20 millimeters of rain, according to meteorological data collected at Dubai International Airport.

The storms intensified around 9 a.m. local Tuesday and continued throughout the day, dumping more rain and hail on the congested city.

By late Tuesday, more than 142 millimeters of rain had drenched Dubai over 24 hours.

An average year sees 94.7 millimeters of rain at Dubai International Airport, a hub for long-haul carrier Emirates.