The 1989 Pacific hurricane season was the annual cycle of tropical cyclone formation over the Pacific Ocean north of the equator and east of the International Date Line (IDL). The season officially began on May 15 in the Eastern Pacific basin proper (east of 140°W) and June 1 in the Central Pacific basin (140°W to the IDL), and ended on November 30 in both areas. This is historically the period during which most tropical cyclogenesis occurs in these respective areas. However, tropical cyclones can form at any time of the year, as demonstrated by the development of Tropical Storm Winona on January 9, more than four months before the official start of the season. Activity ceased on October 19 with the dissipation of Tropical Depression .

Activity during the 1989 season was generally near average. A total of 18 named tropical storms formed, nine of which strengthened into hurricanes. Four storms became major hurricanes by reaching Category 3 or higher on the five-level Saffir–Simpson scale. There were also seven tropical depressions which remained below tropical storm status. While Winona was the only tropical cyclone to form in the Central Pacific basin in 1989, several tropical depressions and Hurricane Dalilia entered the region by crossing 140°W from the east.

Three tropical cyclones made landfall this season, all in Mexico. Hurricane Cosme struck Guerrero at Category 1 strength in June. Heavy rainfall precipitated severe floods that killed at least 30 people. In late August, the compact yet powerful Hurricane Kiko came ashore in southern Baja California Sur as a Category 3 major hurricane, though little impact was reported in comparison to Kiko's intensity. After greatly weakening from its Category 4 peak intensity, Hurricane Raymond raced across northwestern Mexico in early October, in the process making two landfalls as a tropical storm: first in Baja California Sur, then in Sonora.

This timeline documents tropical cyclone formations, strengthening, weakening, landfalls, extratropical transitions, and dissipations during the season. It includes information that was not released during the season, meaning that data from post-storm reviews by the National Hurricane Center (NHC) and the Central Pacific Hurricane Center (CPHC), including a storm which was not operationally 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 was then located. Prior to 2015, two time zones were utilized in the Eastern Pacific basin: Pacific for the Eastern Pacific, and Hawaii−Aleutian for the Central Pacific. 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 NHC 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. __TOC__

Timeline of events

January January 9 12:00 UTC (2:00 a.m. HST) at An off-season tropical cyclone, Tropical Depression 01W, develops from an area of unsettled weather while located about 725 mi (1,165 km) east-southeast of Honolulu, Hawaii.

January 13 18:00 UTC (8:00 a.m. HST) at Tropical Depression 01W strengthens into Tropical Storm Winona while located about 715 mi (1,150 km) west of the Hawaiian island of Kauaʻi.

January 14

00:00 UTC (2:00 p.m. HST, January 13) at Tropical Storm Winona attains maximum sustained winds of 45 mph (75 km/h)—its highest while in the Central Pacific basin—accompanied by an unknown central pressure while located about 810 mi (1,305 km) west of Kauaʻi.

January 15 12:00 UTC (2:00 a.m. HST) at Tropical Storm Winona crosses the International Date Line (IDL) into the Western Pacific basin while located about 785 mi (1,260 km) east of Wake Island, thereby becoming part of the annual typhoon season.

May May 15 The 1989 Eastern Pacific hurricane season officially begins.

May 31 18:00 UTC (11:00 a.m. PDT) at Tropical Depression develops from an area of unsettled weather while located about 925 mi (1,490 km) south-southwest of the southern tip of the Baja California peninsula.

June June 1 The 1989 Central Pacific hurricane season officially begins. 06:00 UTC (11:00 p.m. PDT, May 31) at Tropical Depression strengthens into Tropical Storm Adolph while located about 955 mi (1,540 km) south-southwest of the southern tip of the Baja California peninsula.

June 2

00:00 UTC (5:00 p.m. PDT, June 1) at Tropical Storm Adolph attains its peak intensity, with maximum sustained winds of 65 mph (100 km/h) and a minimum central pressure of , while located about 1,020 mi (1,640 km) southwest of the southern tip of the Baja California peninsula.

June 4 18:00 UTC (11:00 a.m. PDT) at Tropical Storm Adolph weakens into a tropical depression while located about 1,345 mi (2,170 km) west-southwest of the southern tip of the Baja California peninsula.

June 5 18:00 UTC (11:00 a.m. PDT) at Tropical Depression Adolph is last noted as a tropical cyclone while located about 1,475 mi (2,370 km) west-southwest of the southern tip of the Baja California peninsula, dissipating shortly thereafter.

June 15 18:00 UTC (11:00 a.m. PDT) at Tropical Depression develops from a tropical wave while located about 570 mi (915 km) west-southwest of Acapulco, Guerrero.

June 16 18:00 UTC (11:00 a.m. PDT) at Tropical Depression strengthens into Tropical Storm Barbara while located about 520 mi (835 km) west-southwest of Acapulco.

June 18

00:00 UTC (5:00 p.m. PDT, June 17) at Tropical Storm Barbara strengthens into a Category 1 hurricane on the Saffir–Simpson scale while located about 485 mi (780 km) south of the southern tip of the Baja California peninsula. 06:00 UTC (11:00 p.m. PDT, June 17) at Hurricane Barbara attains its peak intensity, with maximum sustained winds of 80 mph (130 km/h) and a minimum central pressure of , while located about 460 mi (740 km) south of the southern tip of the Baja California peninsula. 18:00 UTC (11:00 a.m. PDT) at Tropical Depression develops from a tropical wave while located about 290 mi (465 km) southeast of Acapulco.

June 19 00:00 UTC (5:00 p.m. PDT, June 18) at Hurricane Barbara weakens into a tropical storm while located about 445 mi (715 km) south-southwest of the southern tip of the Baja California peninsula.

June 20 00:00 UTC (5:00 p.m. PDT, June 19) at Tropical Storm Barbara weakens into a tropical depression while located about 490 mi (790 km) southwest of the southern tip of the Baja California peninsula. 00:00 UTC (5:00 p.m. PDT, June 19) at Tropical Depression strengthens into Tropical Storm Cosme while located about 270 mi (435 km) south of Acapulco.

June 21 00:00 UTC (5:00 p.m. PDT, June 20) at Tropical Depression Barbara is last noted as a tropical cyclone while located about 595 mi (955 km) southwest of the southern tip of the Baja California peninsula, dissipating shortly thereafter. 12:00 UTC (5:00 a.m. PDT) at Tropical Storm Cosme strengthens into a Category 1 hurricane while located about 245 mi (400 km) south of Acapulco.

June 22

00:00 UTC (5:00 p.m. PDT, June 21) at Hurricane Cosme attains its peak intensity, with maximum sustained winds of 85 mph (140 km/h) and a minimum central pressure of . 04:00 UTC (9:00 p.m. PDT, June 21) at Hurricane Cosme makes landfall about 60 mi (95 km) east of Acapulco with maximum sustained winds of 80 mph (130 km/h) and a central pressure of . 12:00 UTC (5:00 a.m. PDT) at Hurricane Cosme weakens into a tropical storm over land while located about 140 mi (220 km/h) north-northeast of Acapulco.

June 23 00:00 UTC (5:00 p.m. PDT, June 22) at Tropical Storm Cosme weakens into a tropical depression over land while located about 225 mi (360 km) south-southwest of Brownsville, Texas. 12:00 UTC (5:00 a.m. PDT) at Tropical Depression Cosme is last noted as a tropical cyclone over land while located about 35 mi (55 km) west of Brownsville, dissipating shortly thereafter.

July July 9 00:00 UTC (5:00 p.m. PDT, July 8) at Tropical Depression develops from an area of unsettled weather while located about 1,610 mi (2,595 km) southwest of the southern tip of the Baja California peninsula. 00:00 UTC (5:00 p.m. PDT, July 8) at Tropical Depression develops from an area of unsettled weather while located about 1,170 mi (1,880 km) southwest of the southern tip of the Baja California peninsula. 18:00 UTC (11:00 a.m. PDT) at Tropical Depression attains its peak intensity, with maximum sustained winds of 35 mph (55 km/h) and an unknown central pressure, while located about 1,780 mi (2,865 km) west-southwest of the southern tip of the Baja California peninsula.

July 10 00:00 UTC (5:00 p.m. PDT, July 9) at Tropical Depression attains its peak intensity, with maximum sustained winds of 35 mph (55 km/h) and an unknown central pressure, while located about 1,190 mi (1,920 km) southwest of the southern tip of the Baja California peninsula.

July 11 12:00 UTC (2:00 a.m. HST) at Tropical Depression crosses 140°W into the Central Pacific basin while located about 1,135 mi (1,825 km) east-southeast of South Point, Hawaii. 12:00 UTC (5:00 a.m. PDT) at Tropical Depression develops from an Intertropical Convergence Zone (ITCZ) disturbance while located about 885 mi (1,425 km) south of the southern tip of the Baja California peninsula.

July 12 18:00 UTC (11:00 a.m. PDT) at Tropical Depression strengthens into Tropical Storm Dalilia while located about 910 mi (1,465 km) south-southwest of the southern tip of the Baja California peninsula.

July 13 06:00 UTC (11:00 p.m. PDT, July 12) at After weakening slightly, Tropical Depression reattains its peak intensity while located about 1,785 mi (2,870 km) west-southwest of the southern tip of the Baja California peninsula. 18:00 UTC (8:00 a.m. HST) at Tropical Depression is last noted as a tropical cyclone while located about 275 mi (445 km) southeast of South Point, dissipating shortly thereafter. 18:00 UTC (11:00 a.m. PDT) at Tropical Storm Dalilia strengthens into a Category 1 hurricane while located about 985 mi (1,585 km) southwest of the southern tip of the Baja California peninsula.

July 14

00:00 UTC (2:00 p.m. HST, July 13) at Tropical Depression crosses 140°W into the Central Pacific basin while located about 1,155 mi (1,860 km) east-southeast of South Point. 18:00 UTC (8:00 a.m. HST) at Tropical Depression is last noted as a tropical cyclone while located about 875 mi (1,410 km) southeast of South Point, dissipating shortly thereafter.

July 15 00:00 UTC (5:00 p.m. PDT, July 14) at Tropical Depression develops from an area of unsettled weather while located about 635 mi (1,020 km) south of the southern tip of the Baja California peninsula.

July 16 12:00 UTC (5:00 a.m. PDT) at Tropical Depression attains its peak intensity, with maximum sustained winds of 35 mph (55 km/h) and an unknown central pressure, while located about 830 mi (1,335 km) southwest of the southern tip of the Baja California peninsula. 18:00 UTC (11:00 a.m. PDT) at Hurricane Dalilia attains its peak intensity, with maximum sustained winds of 90 mph (150 km/h) and a minimum central pressure of , while located about 1,930 mi (3,105 km) west-southwest of the southern tip of the Baja California peninsula.

July 17 06:00 UTC (8:00 p.m. HST, July 16) at Hurricane Dalilia crosses 140°W into the Central Pacific basin while located about 965 mi (1,555 km) east-southeast of South Point.

July 18 06:00 UTC (11:00 p.m. PDT, July 17) at Tropical Depression is last noted as a tropical cyclone while located about 1,360 mi (2,185 km) west of the southern tip of the Baja California peninsula, dissipating shortly thereafter.

July 19