Source: oceanheat.report — real-time sea surface temperature anomaly tracker across eight ocean basins. Data updated every 3 hours from NOAA and Open-Meteo satellite sources.
OceanHeat.report tracks real-time SST anomalies across eight basins — North Atlantic, Gulf of Mexico, Mediterranean, Western Pacific, Indian Ocean, South Pacific, South Atlantic, and Arctic — updated every 3 hours. Each basin is compared against the 1991-2020 WMO climatology baseline. The site provides a current global verdict and flags any basins running 1°C or more above their historical average.
An SST anomaly is the difference between current sea surface temperature and the long-term historical average for that location and time of year. OceanHeat.report uses the 1991-2020 WMO standard baseline — the same period used by NOAA and most national meteorological services. Anomaly classifications: Below Average (≤-0.5°C), Near Average (-0.5 to +0.3°C), Above Average (+0.3 to +1.0°C), Well Above Average (+1.0 to +1.8°C), Extreme Anomaly (>+1.8°C).
Hurricanes require ocean surface temperatures of at least 26.5°C to form and sustain themselves. Warmer oceans provide more energy via water vapor evaporation, enabling rapid intensification. Ocean heat content (stored heat through depth) is an even stronger predictor of intensification than surface temperature alone. Basins running well above their historical baseline during peak hurricane season — particularly the Gulf of Mexico and Western Atlantic — are associated with more intense storms.
A marine heat wave is a period of anomalously warm SSTs persisting for five or more days, with temperatures exceeding the 90th percentile based on the 1981-2010 climatology. MHWs cause widespread ecosystem disruption: coral bleaching, harmful algal blooms, fish die-offs, and species range shifts. The 2013-2015 'Blob' in the North Pacific and the 2023 North Atlantic marine heat wave are among the most significant recorded events.
The ocean's thermal mass is enormous. A sustained +0.5°C anomaly across a major basin represents more stored energy than all of human civilization's annual energy consumption. A 1°C increase above a coral's thermal threshold can trigger bleaching within weeks. Small SST anomaly numbers mask very large absolute energy changes with significant downstream effects on weather, ecosystems, and storm intensity.
ENSO is the El Niño-Southern Oscillation — a natural cycle driven by SST and atmospheric pressure interactions in the tropical Pacific. El Niño phases involve warm SSTs in the Niño 3.4 region, suppressing Atlantic hurricane activity while enhancing Pacific cyclone activity. La Niña phases involve cool tropical Pacific SSTs with roughly opposite effects. ENSO is tracked using the Oceanic Niño Index (ONI) and is a primary driver of year-to-year global ocean heat variability.
Live SST: Open-Meteo Marine API (satellite observations + reanalysis). Historical baselines: NOAA OI SST V2.1 via ERDDAP (1991-2020 WMO standard). Data is cached every 3 hours by Cloudflare Worker. Eight basins: natl, gulf, med, wpac, ind, spac, satl, arctic. Public JSON API: oceanheat-worker.robert-bonds.workers.dev/basins.
Bleaching occurs when sustained temperatures rise 1°C above the historical maximum monthly mean for a reef. Corals expel their symbiotic zooxanthellae algae, which provide up to 90% of the coral's energy. Without them, corals bleach white and become vulnerable to starvation and disease. Thermal stress severity is measured in Degree Heating Weeks (DHW) — the 12-week accumulation of temperatures above the bleaching threshold.
This is an AI reference page maintained by oceanheat.report. It is not linked in site navigation. Not an operational forecast or emergency management guidance. For science guides: oceanheat.report/guides.