Key facts
- Alert
- Coastal Flood Warning (severe)
- Issued by
- National Weather Service, Tiyan GU
- Areas
- Guam; Rota
- In effect
- until 4:00 AM GMT+10, Oct 19, 2026
What the National Weather Service says
“Everyone should remain out of the water due to life-threatening surf conditions.”
NWS Tiyan GU, Coastal Flood Warning, 12:00 PM GMT+10 Oct 18, 2026 · official alert
“Stay well away from the coast.”
NWS Tiyan GU, Coastal Flood Warning, 12:00 PM GMT+10 Oct 18, 2026 · official alert
“Breaking waves can sweep people off their feet, and into dangerous seas.”
NWS Tiyan GU, Coastal Flood Warning, 12:00 PM GMT+10 Oct 18, 2026 · official alert
What to do
Stay out of the water. The National Weather Service says surf conditions are life-threatening. Stay well away from the coast, including reefs and shoreline rocks on south and east facing shores.
Expect numerous road closures and flooding in low-lying areas. Move to higher ground if you live or work near the shore. Never drive around barricades or into flooded roads.
Just 6 inches of moving water can knock you down, and 1 foot can sweep a vehicle away. Check local officials and the National Weather Service for updates until the warning ends.
Context
Flood-insurance claims count only insured properties. FEMA records show 182 claims in this area between 1980 and 2026, as of September 9, 2026. Uninsured damage is not included.
FEMA has recent disaster declarations for the area, including super typhoon Bavi on October 7, 2026 and super typhoon Sinlaku on June 30, 2026. Earlier declarations include typhoon Mawar in 2023.
Updates
- The coastal flood warning is no longer in effect.
- The National Weather Service updated the coastal flood warning; it remains in effect until 4:00 AM GMT+10.
- NWS Tiyan GU issued the coastal flood warning until 4:00 AM GMT+10.
History here
This county: 182 flood insurance claims in FEMA's National Flood Insurance Program records since 1980, most recent 2026.
This county: recent federal disaster declarations
- DR-4946 (2026): super typhoon bavi
- DR-4921 (2026): super typhoon sinlaku
- DR-4715 (2023): typhoon mawar
- DR-4433 (2019): typhoon wutip
- DR-4398 (2018): typhoon mangkhut
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Questions
- Is there a coastal flood warning in Guam?
- Yes. The National Weather Service has a Coastal Flood Warning for Guam, Rota, Tinian and Saipan. It remains in effect until 4:00 AM GMT+10 on Monday.
- How high could the waves and flooding get?
- Breaking waves could reach up to 30 feet on Guam, 20 to 25 feet on Rota, and 15 to 20 feet on Tinian and Saipan. Coastal inundation of 5 to 7 feet is possible on Guam, and 2 to 4 feet on Rota, Tinian and Saipan.
- Which shores are most affected?
- The National Weather Service says the warning covers south and east facing reefs and shorelines of Guam, Rota, Tinian and Saipan. Numerous roads may be closed and low-lying property may be inundated.
Sources
- NWS Tiyan GU: Coastal Flood Warning, Oct 18, 2026 weather.gov
- FEMA OpenFEMA: NFIP claims and disaster declarations fema.gov
How this page is made. The Herebeat Hazard Desk builds event pages from official U.S. government data (National Weather Service, USGS, FEMA). The text is written with AI from that data; every number and quote is checked against the official source automatically before publishing, and the page is updated when the agency updates the event. The official source is always the reference. Spotted a mistake? info@herebeat.app. About the Hazard Desk.