Notice: CRW's twice-weekly 50 km products will update around 2 pm on Mondays and Thursdays (U.S. Eastern Time) starting from 1 February 2016, using a new 50 km SST analysis. Click here to see details.
Coral Reef Watch 50-km Satellite Monitoring
NOAA Coral Reef Watch is now featuring its new Daily 5-km Satellite Coral Bleaching Thermal Stress Monitoring Product Suite on this website. Access to our heritage suite of operational 50-km satellite monitoring products will still be possible for the next several months. We encourage all of our users to look over the new 5-km products and provide feedback to us at

Click on buttons below image to change parameter; click on image to navigate to parameter's web page.

The NOAA Coral Reef Watch program's satellite data provide current reef environmental conditions to quickly identify areas at risk for coral bleaching, where corals lose the symbiotic algae that give them their distinctive colors. If a coral is severely bleached, disease and partial mortality become likely, and the entire colony may die.

Continuous monitoring of sea surface temperature at global scales provides researchers and stakeholders with tools to understand and better manage the complex interactions leading to coral bleaching. When bleaching conditions occur, these tools can be used to trigger bleaching response plans and support appropriate management decisions.

The Coral Reef Watch mission is to utilize remote sensing and in situ tools for near-real-time and long term monitoring, modeling and reporting of physical environmental conditions of coral reef ecosystems.

Coral Reef Watch is part of the NOAA Coral Reef Conservation Program (CRCP) and the National Environmental Satellite, Data, and Information Service (NESDIS). A brief history of Coral Reef Watch's early years is featured in "NOAA Celebrates 200 Years of Science, Service, and Stewardship."

Our satellite product suites are a key component of NOAA's monitoring system for coral reef ecosystems, the Coral Reef Ecosystem Integrated Observing System (CREIOS), as well as the NOAA CRCP's National Coral Reef Monitoring Program (NCRMP).

If you have questions, please visit our online tutorial (based on the 50-km products presently) or the products overview page.