Timeline of the 2009 North Indian Ocean cyclone season

Timeline of the 2009 North Indian Ocean cyclone season
Season summary map
Season boundaries
First system formed	April 14, 2009
Last system dissipated	December 16, 2009
Strongest system
Name	Aila
Maximum winds	110 km/h (70 mph) (3-minute sustained)
Lowest pressure	968 hPa (mbar)
Longest lasting system
Name	Ward
Duration	6 days
Storm articles Cyclone Bijli Cyclone Aila Cyclone Phyan
Other years 2007, 2008, 2009, 2010, 2011

This is a timeline of the 2009 North Indian Ocean cyclone season, which contains details of when a depression forms, strengthens, weakens, makes landfalls, and dissipates during the 2009 North Indian Ocean cyclone season. It also includes information from post-storm analysis by the Joint Typhoon Warning Center (JTWC), and the India Meteorological Department (IMD) who run the Regional Specialized Meteorological Center in New Delhi, India. RSMC New Delhi's area of responsibility is officially between 45°E and 100E which is east of the Horn of Africa and west of the Malay Peninsula. There are two main seas within the North Indian Ocean, the Arabian Sea and the Bay of Bengal. For storms, these are abbreviated as BOB and ARB by the IMD.

So far this season there have been four depressions that have formed; three in the Bay of Bengal and one in the Arabian Sea. Three of the depressions have intensified further with two becoming cyclonic storms with the names Bijli and Aila being assigned to them, whilst the other depression became a Deep Depression. Aila intensified further and peaked as a Severe Cyclonic Storm.