Coral reef and patch reefsHard bottomSeagrassGlints: today's heat alert, watch to Alert Level 5
Heat stress since 1985
About this dataEach year's highest Degree Heating Weeks (°C-weeks) at NOAA Coral Reef Watch's 5 km regional virtual stations for the Florida Keys and for Southeast Florida, from satellite sea surface temperatures. Degree Heating Weeks add up how far the water runs above the warmest month's normal over 12 weeks. At 4, significant bleaching is likely; at 8, heat-sensitive corals start dying; at 16, more than half the corals; at 20, more than 80%. This year's value is so far.