For each beach, Playas Hoy checks official sources and models and sums up what it finds in an assessment for today, in the beach's local time. Spanish and English use the same data and the same rules.
Who makes Playas Hoy
Playas Hoy is a product of GTM Labs, a technology company from Porto Alegre, Brazil, that builds and runs digital products that organize information and simplify choices.
Playas Hoy uses automation and artificial intelligence to collect, organize and write part of its content, reviewed by the responsible editor under the GTM Labs Editorial policy.
How the assessment is formed
There are four possible results: "Good beach day", "Could be worth it", "Not recommended today" and "Not enough data for a verdict".
A serious official warning makes the result "Not recommended today": a tsunami alert, a severe or extreme SMN warning, a cyclone warning zone on this coast, or tropical-storm winds forecast over the beach today. Lightning close to the beach does the same.
Other warnings and readings cap the result at "Could be worth it": a moderate SMN warning, a cyclone watch zone, sargassum right next to the beach, a SEMAR ground-swell warning in force, a latest COFEPRIS result "not suitable" still within its validity, or official warning sources not responding.
Everything else (rain, wind, modelled waves, air and water temperature, lightning in the region) adds or subtracts within those limits. What is in favour never offsets a warning.
Waves are the model's total wave height offshore, and only ever subtract. At beaches sheltered by a bay, cove or reef, reviewed one by one, they do not weigh: the model measures the sea outside the bay. The model can underestimate the surf during a hurricane; official warnings and the beach flag come first.
With too little data to assess, the beach gets "Not enough data for a verdict" instead of a guess. Missing data never counts as good.
The thresholds are being calibrated against external sources and may change.
What we do not claim
No data means no data: when a source does not respond, the page says so and shows no default value.
Water quality is the latest COFEPRIS monitoring, with its date; it is not today's condition.
Sargassum is a satellite detection with the image date, not a report from the beach.
The tide is a model estimate, not a tide gauge measurement. Air quality is an estimate using the NOM-172-SEMARNAT-2023 bands on a model, not a monitoring station measurement.
Chlorophyll and transparency are satellite readings. They do not indicate algae or water quality today and are not part of the assessment.
High waves are not "ground swell": the page only uses that term when SEMAR has issued a warning.
Playas Hoy does not replace official warnings or lifeguard instructions.
Sources, licences and credits
Each source keeps its licence. Credits required by a source appear next to its data on the beach page and are listed here in their original wording.
Contains modified Copernicus Atmosphere Monitoring Service Information [year]. Neither the European Commission nor ECMWF is responsible for any use that may be made of the information it contains.
Satellite water transparency and chlorophyll (product OCEANCOLOUR_GLO_BGC_L3_NRT_009_101), with the reading date. Information only; not part of the assessment.
Active warnings (CAP format) whose area reaches the beach. Playas Hoy adapts the data: it applies a margin around the polygon and summarizes the warning.