The fourth named storm of the 2023 North Indian Ocean cyclone season, Hamoon formed from a low-pressure area over the west-central Bay of Bengal on 21 October.

Prior to Hamoon's landfall, officials in Bangladesh ordered the evacuation of over 1.5 million people as it was expected to have a severe impact on the nation.

On 12 October, in their extended range outlook, the India Meteorological Department (IMD) noted that in a few days, tropical cyclonegenesis was likely to occur in the Bay of Bengal.

[5] A few hours later, the Joint Typhoon Warning Center (JTWC) began tracking the system, noting that the low-level circulation was in an favorable environment for development, with low 5–10 mph (10–20 km/h) vertical wind shear and warm sea surface temperatures (SSTs) of 29–30 °C (84–86 °F), only offset by the disturbance's poor outflow.

[3] Around six hours later, the JTWC issued a TCFA on the deep depression, noting that it had developed convective banding across all quadrants and good poleward outflow.

[15] However, as it tracked northeastwards due to a trough embedded in the westerlies, it crossed into a region of high wind shear,[3] weakening into a severe cyclonic storm a few hours later.

[16] Later that day, Hamoon made landfall south of Chittagong, Bangladesh as a severe tropical storm,[3] prompting the JTWC to stop tracking it.

[20] The Chittagong Port Authority dispatched eighty-eight ships to the deep sea in order to safeguard against potential damages from Cyclone Hamoon.

[22] In St. Martin's Island, over fifteen hundred tourists were ordered to leave due to adverse weather conditions caused by Hamoon, being sent back to nearby Teknaf using three ships.

[25] As Hamoon developed into a deep depression on 23 October, the IMD issued a yellow warning in Odisha, for the districts of Bhadrak, Kendrapara, and Jagatsinghpur.

Additionally, fishermen planning to venture in and offshore Odisha, West Bengal, Bangladesh, and the northern coast of Myanmar were discouraged by the IMD.

[30] Finally, in Myanmar, authorities in Rakhine State were issued an alert by the Department of Meteorology and Hydrology (DMH), being on standby and conducting preparedness tests.

[34] As Hamoon made landfall, gusts from the cyclone disrupted the power supply to the city of Cox's Bazar, causing blackouts.

A peak gust of 148 km/h (92 mph) was recorded in the city at 8:12pm local time, causing many houses and rice paddy fields to be levelled by intense winds.