NOAA Coral Reef Watch will discontinue all operational twice-weekly 50km satellite coral bleaching heat stress monitoring products in April 2020.

These products are being replaced with higher resolution daily 5km satellite products.

Archived 50km data and images will still be available at If you need any assistance, please contact


50km Coral Bleaching HotSpot
clickable global map of coral bleaching hotspots
hotspots in Mediterranean and Red Sea hotspots around India hotspots east of Japan hotspots around Hawaii hotspots around Central America hotspots West of Africa hotspots in Mediterranean and Red Sea hotspots around southern Africa hotspots in the southern Indian Ocean hotspots around Australia hotspots in the South Pacific hotspots west of South America hotspots east of Brazil hotspots around southern Africa
Click on the image to zoom in.

Current images: Global | E.Hem. | W.Hem. | Pacific | Caribbean | Coral Triangle

Data Formats Available

images Image Archives
Regional imagery and image archives from NOAA/NESDIS' Office of Satellite and Product Operations (OSPO).
Google Earth Google Earth
All of our satellite data products are available on Google Earth.
Virtual Stations 50km Virtual Stations
Imagery, graphs, ASCII data, and e-mail alerts for reef pixels around the world.
animations Animations
Data animations and downloadable animated GIF files from NOAA/NESDIS OSPO.

The NOAA Coral Reef Watch (CRW) twice-weekly global 50km Coral Bleaching HotSpot product presented here measures occurrence and magnitude of instantaneous heat stress, potentially resulting in coral bleaching. The scale goes from 0 to 5 °C. HotSpot values of 1 °C or more indicate heat stress leading to coral bleaching and are highlighted in yellow to red colors. Spatial resolution is one-half degree precisely.

Additional description in the 50km products tutorial.
Technical details on the methodology page and in Liu et al. 2013.