The 2008 North Indian cyclone season was one of the most disastrous tropical cyclone seasons in modern history, with tropical cyclones leaving more than 140,000 people dead and causing more than US$15 billion in damage, making it the costliest season in the North Indian Ocean, until it was made second in 2020. The season has no official bounds but cyclones tend to form between April and December. These dates conventionally delimit the period of each year when most tropical cyclones form in the northern Indian Ocean. There are two main seas in the North Indian Ocean—the Bay of Bengal to the east of the Indian subcontinent and the Arabian Sea to the west of India. The official Regional Specialized Meteorological Centre in this basin is the India Meteorological Department (IMD), while the Joint Typhoon Warning Center releases unofficial advisories. An average of four to six storms form in the North Indian Ocean every season with peaks in May and November. Cyclones occurring between the meridians 45°E and 100°E are included in the season by the IMD.