A simple question in Tenerife led to building something better.
We were planning a trip to Tenerife. Like most beach lovers, we checked the weather app before booking — just wanted to know if we could swim.
The app said 17°C. Chilly. But photos of the beaches showed people swimming everywhere.
Something didn't add up...
During the hiking trip in Agana, our guide Alex revealed the secret: the official weather station sits at high elevation. In Tenerife, roughly every 100 meters higher means about 1°C lower. Suddenly everything made sense.
Most weather apps show air temperature measured inland or at altitude. They do not show real sea surface temperature near the beach where you actually want to swim.
That means travelers routinely underestimate — or overestimate — how warm the ocean really is at their destination.
This tool uses satellite-derived sea surface temperature data from Copernicus Marine — the same data source used by oceanographers and climate researchers.
Instead of guessing, you click directly on any coastline and see what the water is actually like near that exact spot, updated daily.
"Is the sea warm enough to swim here?"
Help travelers plan better beach days. Help swimmers avoid surprises. That's it.