Timeline of the 2009 Pacific hurricane season

The 2009 Pacific hurricane season officially started on May 15 in the East Pacific Ocean, and on June 1 in the Central Pacific; they both ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the Pacific basin. No tropical cyclones formed during the month of May, making 2009 the first time that no tropical cyclones formed during May since 1999. The first tropical cyclone of the year, Tropical Depression One-E, formed June 18, and dissipated the following day. The first named storm of the season, Hurricane Andres formed on June 21. The final storm of the season, Neki, dissipaed on October 27.

This timeline documents tropical cyclone formations, strengthening, weakening, landfalls, extratropical transitions, and dissipations during the season. It includes information that was not released throughout the season, meaning that data from post-storm reviews by the National Hurricane Center and the Central Pacific Hurricane Center, such as a storm that was not initially warned upon, has been included.

The time stamp for each event is first stated using Coordinated Universal Time (UTC), the 24-hour clock where 0000 = midnight UTC. The NHC uses both UTC and the time zone where the center of the tropical cyclone is currently located. Prior to 2015, two time zones were utilized in the Eastern Pacific basin: Pacific east of 140°W, and Hawaii−Aleutian from 140°W to the International Date Line. In this timeline, the respective area time is included in parentheses. Additionally, figures for maximum sustained winds and position estimates are rounded to the nearest 5 units (miles, or kilometers), following National Hurricane Center practice. Direct wind observations are rounded to the nearest whole number. Atmospheric pressures are listed to the nearest millibar and nearest hundredth of an inch of mercury.