No, Koinu is no longer active. It dissipated or transitioned into an extratropical cyclone on 2023-10-10T00:00:00.000Z.
Koinu formed on 2023-09-27T12:00:00.000Z and dissipated on 2023-10-10T00:00:00.000Z, reaching a peak intensity of tropical_depression.
Koinu achieved maximum sustained winds of approximately 220 km/h (119 kt / 137 mph) and a minimum central pressure of approximately 936 hPa.
According to current track forecasts, Koinu is expected to pass near Macau with a closest approach of approximately 56 km, suggesting a higher potential for direct impacts.
According to current track forecasts, Koinu is expected to pass near Kaohsiung with a closest approach of approximately 66 km, suggesting a higher potential for direct impacts.
According to current track forecasts, Koinu is expected to pass near Hong Kong with a closest approach of approximately 69 km, suggesting a higher potential for direct impacts.
According to current track forecasts, Koinu is expected to pass near Shenzhen with a closest approach of approximately 94 km, suggesting a higher potential for direct impacts.
Projected rainfall totals of approximately 150-300 mm (6-12 inches) may occur in affected areas, creating risks of flash flooding and urban flooding.
Yes. Tropical systems carry abundant moisture, and outer rainbands can trigger flash flooding, river flooding, and urban flooding.
Adjust preparations based on the storm category and official advice. Secure outdoor items, prepare emergency supplies, keep backup power available, and follow official advisories.
Evacuation decisions must strictly follow official directives issued by local emergency management agencies. If an evacuation order is issued, evacuate immediately using designated routes. Do not rely solely on a single forecast model.
StormAtlas regularly updates based on publicly available data from international meteorological agencies. The latest data update was at August 12, 2026 at 05:30 PM.
Koinu developed over warm ocean waters under conditions of high atmospheric moisture and low vertical wind shear.
The forecast path integrates data from multiple international meteorological agencies and numerical weather prediction models (such as NHC, JMA, JTWC, and CMA) using ensemble forecasting methods to generate probabilistic forecast tracks.
Storm Timeline
Koinu at 20.6°N, 111.3°E as Tropical Depression with winds of 36 km/h (22 mph)
Koinu at 20.8°N, 111.5°E as Tropical Depression with winds of 40 km/h (25 mph)
Koinu at 20.9°N, 111.9°E as Tropical Depression with winds of 43 km/h (27 mph)
Koinu at 21.0°N, 112.2°E as Tropical Depression with winds of 50 km/h (31 mph)
Koinu at 21.2°N, 112.4°E as Tropical Depression with winds of 54 km/h (34 mph)
Koinu at 21.4°N, 112.5°E as Tropical Storm with winds of 65 km/h (40 mph)
Koinu at 21.5°N, 112.7°E as Tropical Storm with winds of 72 km/h (45 mph)
Koinu at 21.6°N, 113.0°E as Tropical Storm with winds of 83 km/h (52 mph)
Koinu at 21.7°N, 113.3°E as Tropical Storm with winds of 83 km/h (52 mph)
Koinu at 21.7°N, 113.3°E as Tropical Storm with winds of 97 km/h (60 mph)
Koinu at 21.7°N, 113.4°E as Tropical Storm with winds of 104 km/h (65 mph)
Koinu at 21.7°N, 113.4°E as Tropical Storm with winds of 108 km/h (67 mph)
Koinu at 21.7°N, 113.5°E as Tropical Storm with winds of 115 km/h (71 mph)
Koinu at 21.7°N, 113.6°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 122 km/h (76 mph)
Koinu at 21.7°N, 113.7°E as Tropical Storm with winds of 101 km/h (63 mph)
Koinu at 21.7°N, 113.7°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 133 km/h (83 mph)
Koinu at 21.7°N, 113.8°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 140 km/h (87 mph)
Koinu at 21.7°N, 113.8°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 148 km/h (92 mph)
Koinu at 21.7°N, 113.9°E as Category 2 (equivalent to Category 1 Hurricane) with winds of 151 km/h (94 mph)
Koinu at 21.7°N, 114.0°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 158 km/h (98 mph)
Koinu at 21.7°N, 114.0°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 119 km/h (74 mph)
Koinu at 21.7°N, 114.1°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 162 km/h (101 mph)
Koinu at 21.7°N, 114.1°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 158 km/h (98 mph)
Koinu at 21.6°N, 114.2°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 155 km/h (96 mph)
Koinu at 21.6°N, 114.2°E as Category 2 (equivalent to Category 1 Hurricane) with winds of 151 km/h (94 mph)
Koinu at 21.6°N, 114.3°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 151 km/h (94 mph)
Koinu at 21.6°N, 114.3°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 130 km/h (81 mph)
Koinu at 21.6°N, 114.4°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 144 km/h (89 mph)
Koinu at 21.6°N, 114.4°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 144 km/h (89 mph)
Koinu at 21.5°N, 114.5°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 144 km/h (89 mph)
Koinu at 21.5°N, 114.5°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 140 km/h (87 mph)
Koinu at 21.5°N, 114.6°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 140 km/h (87 mph)
Koinu at 21.5°N, 114.6°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 130 km/h (81 mph)
Koinu at 21.4°N, 114.8°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 148 km/h (92 mph)
Koinu at 21.4°N, 114.9°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 137 km/h (85 mph)
Koinu at 21.3°N, 115.0°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 169 km/h (105 mph)
Koinu at 21.3°N, 115.1°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 148 km/h (92 mph)
Koinu at 21.2°N, 115.2°E as Category 3 (equivalent to Category 3 Hurricane) with winds of 191 km/h (119 mph)
Koinu at 21.2°N, 115.2°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 155 km/h (96 mph)
Koinu at 21.1°N, 115.3°E as Category 3 (equivalent to Category 3 Hurricane) with winds of 191 km/h (119 mph)
Koinu at 21.1°N, 115.4°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 155 km/h (96 mph)
Koinu at 21.1°N, 115.6°E as Category 3 (equivalent to Category 3 Hurricane) with winds of 191 km/h (119 mph)
Koinu at 21.2°N, 115.7°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 155 km/h (96 mph)
Koinu at 21.3°N, 116.0°E as Category 3 (equivalent to Category 3 Hurricane) with winds of 191 km/h (119 mph)
Koinu at 21.4°N, 116.3°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 148 km/h (92 mph)
Koinu at 21.6°N, 116.6°E as Category 3 (equivalent to Category 3 Hurricane) with winds of 184 km/h (114 mph)
Koinu at 21.7°N, 116.9°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 148 km/h (92 mph)
Koinu at 21.7°N, 117.3°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 173 km/h (107 mph)
Koinu at 21.8°N, 117.7°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 137 km/h (85 mph)
Koinu at 21.9°N, 118.0°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 148 km/h (92 mph)
Koinu at 21.9°N, 118.4°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 119 km/h (74 mph)
Koinu at 22.0°N, 118.7°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 137 km/h (85 mph)
Koinu at 22.0°N, 119.1°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 130 km/h (81 mph)
Koinu at 22.1°N, 119.5°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 155 km/h (96 mph)
Koinu at 22.1°N, 120.0°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 130 km/h (81 mph)
Koinu at 22.0°N, 120.4°E as Category 3 (equivalent to Category 3 Hurricane) with winds of 184 km/h (114 mph)
Koinu at 22.0°N, 120.8°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 148 km/h (92 mph)
Koinu at 21.9°N, 121.1°E as Category 4 (equivalent to Category 4 Hurricane) with winds of 212 km/h (132 mph)
Koinu at 21.9°N, 121.3°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 166 km/h (103 mph)
Koinu at 22.0°N, 121.6°E as Category 4 (equivalent to Category 4 Hurricane) with winds of 220 km/h (137 mph)
Koinu at 22.0°N, 122.0°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 166 km/h (103 mph)
Koinu at 22.1°N, 122.3°E as Category 4 (equivalent to Category 4 Hurricane) with winds of 216 km/h (134 mph)
Koinu at 22.1°N, 122.7°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 166 km/h (103 mph)
Koinu at 22.2°N, 123.1°E as Category 3 (equivalent to Category 3 Hurricane) with winds of 202 km/h (126 mph)
Koinu at 22.2°N, 123.5°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 155 km/h (96 mph)
Koinu at 22.1°N, 123.8°E as Category 3 (equivalent to Category 3 Hurricane) with winds of 180 km/h (112 mph)
Koinu at 22.0°N, 124.1°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 155 km/h (96 mph)
Koinu at 21.9°N, 124.4°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 169 km/h (105 mph)
Koinu at 21.7°N, 124.6°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 166 km/h (103 mph)
Koinu at 21.5°N, 124.8°E as Category 3 (equivalent to Category 3 Hurricane) with winds of 180 km/h (112 mph)
Koinu at 21.2°N, 124.9°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 166 km/h (103 mph)
Koinu at 20.8°N, 125.0°E as Category 3 (equivalent to Category 3 Hurricane) with winds of 191 km/h (119 mph)
Koinu at 20.5°N, 125.1°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 166 km/h (103 mph)
Koinu at 20.3°N, 125.3°E as Category 3 (equivalent to Category 3 Hurricane) with winds of 198 km/h (123 mph)
Koinu at 20.2°N, 125.5°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 166 km/h (103 mph)
Koinu at 20.1°N, 125.9°E as Category 4 (equivalent to Category 4 Hurricane) with winds of 212 km/h (132 mph)
Koinu at 19.9°N, 126.2°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 155 km/h (96 mph)
Koinu at 19.8°N, 126.4°E as Category 4 (equivalent to Category 4 Hurricane) with winds of 212 km/h (132 mph)
Koinu at 19.6°N, 126.6°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 148 km/h (92 mph)
Koinu at 19.4°N, 127.0°E as Category 3 (equivalent to Category 3 Hurricane) with winds of 198 km/h (123 mph)
Koinu at 19.2°N, 127.3°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 137 km/h (85 mph)
Koinu at 18.9°N, 127.7°E as Category 2 (equivalent to Category 2 Hurricane) with winds of 169 km/h (105 mph)
Koinu at 18.7°N, 128.0°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 119 km/h (74 mph)
Koinu at 18.5°N, 128.3°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 144 km/h (89 mph)
Koinu at 18.3°N, 128.5°E as Tropical Storm with winds of 101 km/h (63 mph)
Koinu at 18.1°N, 128.7°E as Category 1 (equivalent to Category 1 Hurricane) with winds of 130 km/h (81 mph)
Koinu at 17.9°N, 128.9°E as Tropical Storm with winds of 90 km/h (56 mph)
Koinu at 17.7°N, 129.1°E as Tropical Storm with winds of 108 km/h (67 mph)
Koinu at 17.4°N, 129.5°E as Tropical Storm with winds of 90 km/h (56 mph)
Koinu at 17.1°N, 129.8°E as Tropical Storm with winds of 90 km/h (56 mph)
Koinu at 16.9°N, 130.1°E as Tropical Storm with winds of 83 km/h (52 mph)
Koinu at 16.6°N, 130.4°E as Tropical Storm with winds of 79 km/h (49 mph)
Koinu at 16.4°N, 130.7°E as Tropical Storm with winds of 72 km/h (45 mph)
Koinu at 16.2°N, 131.0°E as Tropical Storm with winds of 68 km/h (42 mph)
Koinu at 16.0°N, 131.3°E as Tropical Storm with winds of 65 km/h (40 mph)
Koinu at 15.7°N, 131.6°E as Tropical Depression with winds of 61 km/h (38 mph)
Koinu at 15.4°N, 131.9°E as Tropical Storm with winds of 65 km/h (40 mph)
Koinu at 15.4°N, 132.1°E as Tropical Depression with winds of 54 km/h (34 mph)
Koinu at 15.5°N, 132.6°E as Tropical Storm with winds of 65 km/h (40 mph)
Koinu at 15.5°N, 133.4°E as Tropical Depression with winds of 50 km/h (31 mph)
Koinu at 15.5°N, 134.3°E as Tropical Depression with winds of 43 km/h (27 mph)
Koinu at 15.5°N, 134.8°E as Tropical Depression with winds of 40 km/h (25 mph)
Koinu at 15.4°N, 135.2°E as Tropical Depression with winds of 36 km/h (22 mph)
Koinu at 15.4°N, 135.6°E as Tropical Depression with winds of 36 km/h (22 mph)
Koinu at 15.5°N, 135.9°E as Tropical Depression with winds of 36 km/h (22 mph)
Koinu at 15.5°N, 136.5°E as Tropical Depression with winds of 36 km/h (22 mph)
Koinu at 15.7°N, 137.2°E as Tropical Depression with winds of 36 km/h (22 mph)
Koinu at 15.8°N, 137.8°E as Tropical Depression with winds of 36 km/h (22 mph)
Koinu at 15.8°N, 138.5°E as Tropical Depression with winds of 36 km/h (22 mph)
Koinu at 15.8°N, 139.1°E as Tropical Depression with winds of 32 km/h (20 mph)
Koinu at 15.7°N, 139.9°E as Tropical Depression with winds of 25 km/h (16 mph)
Koinu at 15.7°N, 140.5°E as Tropical Depression with winds of 25 km/h (16 mph)
Koinu at 15.5°N, 141.2°E as Tropical Depression with winds of 25 km/h (16 mph)
Koinu at 15.1°N, 142.2°E as Tropical Depression with winds of 25 km/h (16 mph)
Koinu at 14.7°N, 143.1°E as Tropical Depression with winds of 25 km/h (16 mph)
Koinu at 14.4°N, 143.6°E as Tropical Depression with winds of 25 km/h (16 mph)
Koinu at 14.2°N, 143.8°E as Tropical Depression with winds of 25 km/h (16 mph)
Typhoon Koinu (2023): A Comprehensive Retrospective
1. Formation and Meteorological History
Typhoon Koinu, known in the Philippines as Typhoon Jenny, formed as a tropical depression over the western North Pacific Ocean on September 28, 2023, approximately 1,920 km east of Manila. It gradually intensified while moving westward, becoming a severe typhoon on October 2 with maximum sustained winds of 175 km/h (109 mph). Koinu reached peak intensity as a Category 4-equivalent storm before making landfall over southern Taiwan on October 5. After crossing Taiwan, it weakened but reintensified over the South China Sea, reaching severe typhoon status again on October 6. The storm then moved slowly toward the Pearl River Estuary, but rapidly weakened due to the northeast monsoon, degenerating into a low-pressure area over the coastal waters of Yangjiang on October 9.
2. Impact and Damages
Taiwan: Koinu brought destructive winds and torrential rains to southern Taiwan. One person was killed, 399 were injured, and over 460,000 households experienced power outages. Water supply was disrupted for more than 6,000 households, and around 3,000 people were displaced. Agricultural and infrastructure losses exceeded USD 18 million.
Hong Kong: The Hong Kong Observatory issued the Increasing Gale or Storm Signal No. 9, the second such signal in 2023. Koinu brought record-breaking rainfall: 369.7 mm fell on October 9, more than three times the monthly normal for October. The 24-hour rainfall from October 8-9 reached 439.8 mm, the highest October record. Widespread flooding and landslides occurred.
Macao: Two people were injured, and 19 incidents were reported, including fallen trees and a landslide.
Philippines: Although Koinu did not make landfall, it enhanced the southwest monsoon, causing heavy rains and flooding in parts of Luzon. No direct casualties were reported.
Mainland China: Coastal areas of Guangdong experienced strong winds and heavy rain, but damage was limited due to the storm's rapid weakening.
3. Government Response and Relief Efforts
Taiwan: The Central Emergency Operation Center activated, coordinating evacuations and deploying military resources for rescue and recovery. Power companies worked to restore electricity, and disaster relief funds were allocated.
Hong Kong: The Hong Kong Observatory issued timely warnings, and the Home Affairs Department opened temporary shelters. The Drainage Services Department deployed flood prevention measures.
Macao: The Meteorological and Geophysical Bureau issued warnings, and the Civil Protection Operation Centre activated. Emergency services responded to incidents.
Philippines: The National Disaster Risk Reduction and Management Council (NDRRMC) monitored the enhanced monsoon and issued advisories. Preemptive evacuations were conducted in flood-prone areas.
International: The Joint Typhoon Warning Center (JTWC) and regional meteorological agencies provided forecasts and warnings, facilitating preparedness across affected regions.
