The Coral Reef Temperature Anomaly Database (CoRTAD) is a collection of sea surface temperature (SST) and related thermal stress metrics, developed specifically for coral reef ecosystem applications but relevant to other ecosystems as well. The CoRTAD Version 2 contains global, approximately 4 km resolution SST data on a weekly time scale from 1982 through 2009. It is related to the CoRTAD Version 2 (NODC Accession 0054501), but contains one additional year of data (2009). Version 2 was created in 2009 with a few important updates to the CoRTAD Version 1 (NODC Accession Number 0044419). Whereas Version 1 is in HDF4 Scientific Data Set format, Version 2 is in HDF5. In addition to SST, the CoRTAD contains SST anomaly (SSTA, weekly SST minus weekly climatological SST), thermal stress anomaly (TSA, weekly SST minus the maximum weekly climatological SST), SSTA Degree Heating Week (SSTA_DHW, sum of previous 12 weeks when SSTA >= 1 degree C), SSTA Frequency (number of times over previous 52 weeks that SSTA >= 1 degree C), TSA DHW (TSA_DHW, also known as a Degree Heating Week, sum of previous 12 weeks when TSA >= 1 degree C),and TSA Frequency (number of times over previous 52 weeks that TSA >= 1 degree C). The CoRTAD was created at the NOAA National Oceanographic Data Center in partnership with the University of North Carolina - Chapel Hill, with support from the NOAA Coral Reef Conservation Program.