A warmer ocean. A changing planet.

A temperature map tells one part of the story.

The surface ocean is constantly exchanging heat with the atmosphere and transporting it through currents. A warm colour shows temperature, but it does not tell you whether that temperature is unusual for the place and season.

Ask: warmer than what?

An anomaly compares temperature against a specified reference. The MUR25 anomaly product uses its 2003–2014 climatology. The choice of reference matters; a colour alone cannot establish a marine heatwave or explain its cause.

Make your own observation.

Open the layer, select a location and compare the same season in different years. Look for missing coverage. Treat a visual pattern as the start of a question, not the end of an analysis.