The second named storm of the 2018 North Indian Ocean cyclone season, Mekunu developed out of a low-pressure area on May 21.

The India Meteorological Department estimated 10 minute sustained winds of 175 km/h (110 mph), making Mekunu an extremely severe cyclonic storm.

While passing near Socotra, Cyclone Mekunu dropped heavy rainfall, causing landslides and flooding that killed 20 people.

With very warm ocean temperatures over 29 °C (84 °F) and moderate wind shear, atmospheric conditions were conducive for eventual tropical cyclone development.

[3] The American-based Joint Typhoon Warning Center (JTWC) followed suit and began issuing advisories on the system early on May 22, designating it Tropical Cyclone 02A.

[8] The IMD upgraded Mekunu to an extremely severe cyclonic storm on May 25, estimating peak 3-minute sustained winds of 175 km/h (110 mph).

[11] On May 27, the IMD downgraded Mekunu to a well-marked low-pressure area, near the borders of Oman, Yemen, and Saudi Arabia.

[13] Landslides covered farms, destroyed food stocks, knocked down palm trees, and washed away thousands of animals.

[17] On the Yemeni mainland, flooding rains damaged roads, vehicles, and buildings in Hadhramaut and Al Mahrah Governorates.

[17] Cyclone Mekunu struck Oman at peak intensity,[3] bringing strong winds and heavy rainfall.

[10] The rains collected in area dams,[18] and created lakes in Rub' al Khali, or the Empty Quarter, a large desert that typically receives 30 mm (1.2 in) of annual rainfall.

[23] After the scope of the damage became evident on Socotra, Saudi Arabia, United Arab Emirates (UAE), Qatar, and Kuwait provided shelter, medical, and other emergency supplies.

[17] The United Nations Humanitarian Air Service (UNHAS) carried four flights of food, shelter, and water supplies.

[28] The heavy rainfall from Mekunu created favorable breeding conditions for locusts in the Rub' al Khali, or the Empty Quarter.

By February 2019, a locust infestation had spread across the Arabian Peninsula and into Iran, and later into the Horn of Africa, India, and Pakistan, eventually reaching 10 countries.