Marine Heatwave Tracker

Hobday Categories 1–5 — sustained warm SST anomalies driving coral bleaching and fisheries shifts.

Compiled daily
Strongest MHW category
current peak
Active MHW events
tracked regions
Peak SST anomaly
above climatology
Niño 3.4 anomaly
Niño 3.4
NOAA MHW

Tracked region heatwave map

Cat 1 moderate → Cat 5 beyond extreme (Hobday et al.)

Current MHW category distribution

Regional spotlight

Curated

Marine heatwave news