Indian Ocean Coral Bleaching
Bleaching risk low to moderate at start of 2026
2025 was the 3rd warmest year since 1850, at 1.41 ± 0.09 °C above the 1850–1900 average.
2023-2025 have been the hottest years ever. Unlike during El Niño conditions in 2023 and 2024, the high in 2025 was solely due to human-driven climate warming. Global SST remained well above long-term average into the southern summer, indicating sustained ocean heat content despite weakening La Niña conditions and a neutral Indian Ocean Dipole. Will 2026 be the 4th warmest year ever?
For materials and guidance on responding to coral bleaching and mortality, watch the following video or download the following guide. Bleaching alerts from 2009 to date are available further down the page.
Indian Ocean Bleaching observations Dashboard 2016-2025 click to open the dashboard
Report Coral Bleaching
Submit basic observations on coral bleaching through this embedded window, in the google-form below. All data will be submitted to the global bleaching form supported by the NOAA Coral Reef Watch programme, and made accessible on a WIO regional database under development.
HISTORICAL BLEACHING – 2009 TO PRESENT
All past bleaching alerts, from 2009 to the current year, are in the window below. Click on the relevant year, or scroll left/right within each year for additional alerts. Alerts are published between January and May each year, with fewer alerts when bleaching risk is low.