The season officially started on May 15 in the eastern Pacific—east of 140°W—and began on June 1 in the central Pacific—the region between the International Date Line and 140°W, and ended on November 30.
The 2018 hurricane season was exceptionally active and featured the highest Accumulated Cyclone Energy since reliable records began in 1971.
[3][nb 1] The basin saw above-average activity across all regions from the International Date Line to the west coast of Mexico and Central America.
Instead, low pressures and increased sea surface temperatures associated with the Pacific Meridional Mode supported the development of these intense and long-lived storms.
This timeline documents the formation of tropical cyclones as well as the strengthening, weakening, landfalls, extratropical transitions, and dissipations during the season.