50-km Degree Heating Week
clickable global map of degree heating weeks
DHWs in Mediterranean and Red Sea DHWs around India DHWs east of Japan DHWs around Hawaii DHWs around Central America DHWs West of Africa DHWs in Mediterranean and Red Sea DHWs around southern Africa DHWs in the southern Indian Ocean DHWs around Australia DHWs in the South Pacific DHWs west of South America DHWs east of Brazil DHWs 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 OSDPD.
Google Earth Google Earth
All of our satellite data products are available on Google Earth.
Virtual Stations 50-km 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 OSDPD.
HDF data HDF data files
Raw data in Hierarchical Data Format (HDF), with free NOAA viewing software.

The NOAA Coral Reef Watch (CRW) twice-weekly 50-km satellite coral bleaching Degree Heating Week (DHW) product presented here shows accumulated thermal stress, which can lead to coral bleaching. The scale goes from 0 to 16 degree-weeks. Spatial resolution is one-half degree. The DHW product accumulates the instantaneous bleaching thermal stress (measured by HotSpots) during the most-recent 12-week period. It is directly related to the timing and intensity of coral bleaching. Significant coral bleaching usually occurs when DHW values reach 4 °C-weeks. By the time DHW values reach 8 °C-weeks, widespread bleaching is likely and significant mortality can be expected. Spatial resolution is one-half degrees precisely.

Product description in the tutorial.
Technical details on the methodology page and in Liu et al. 2013.