Timeline of the 2023 Pacific hurricane season

The 2023 Pacific hurricane season was a fairly active Pacific hurricane season. In the eastern Pacific basin (east of 140°W), 17 named storms formed; 10 of those became hurricanes, and 8 further intensified into major hurricanes (category 3 or higher on the 5-level Saffir–Simpson wind speed scale). In the central Pacific basin (between 140°W and the International Date Line), no tropical cyclones formed (for the fourth consecutive season), though four entered into the basin from the east. The season officially began on May 15, 2023, in the eastern Pacific, and on June 1 in the central Pacific; it ended in both on November 30. These dates, adopted by convention, historically describe the period in each year when most tropical cyclogenesis occurs in these regions of the Pacific. The season's first system, Tropical Storm Adrian, developed on June 27, and its last, Tropical Storm Ramon, dissipated on November 26.

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, 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 00:00 = midnight UTC. The NHC uses both UTC and the time zone where the center of the tropical cyclone is currently located. The time zones utilized (east to west) are: Central, Mountain, Pacific and Hawaii. 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.