Data sources
Every number on this site comes from a public dataset. This page lists all of them, what they cover and the licence they are used under.
Climate and sea figures are long-term averages for 1991–2020, plus the month-by-month values for 2020–2025. None of it is a forecast.
| Source | Dataset | Period | Resolution | Commercial use | Licence |
|---|---|---|---|---|---|
| Agencia Portuguesa do Ambiente | Praias acessiveis (programa Praia Acessivel, Praia para Todos!) | current season | point | ✓ yes | CC BY 4.0 |
| EOX Sentinel-2 cloudless 2016/2017 | s2cloudless 2016, and 2017 where 2016 is missing | 2016-2017 | 10 m | ✓ yes | CC BY 4.0 |
| European Environment Agency | Bathing Water Directive - Status of bathing water 1990-2025 | bathing seasons 1990-2025 | point (official bathing site) | ✓ yes | CC BY 4.0 |
| GeoNames | allCountries (worldwide geographic dump) | point | ✓ yes | Creative Commons Attribution 4.0 | |
| NASA POWER | Climatology, monthly and daily point data (MERRA-2 / CERES SYN1deg) | 1991-2020 averages; 2020-2025 month by month; daily rain 1991-2025 | 0.5 degrees (~55 km) | ✓ yes | US Government data — no use restrictions |
| NOAA OISST v2.1 | Optimum Interpolation SST — long-term and yearly monthly means | 1991-2020 averages; 2020-2025 month by month | 0.25 degrees (~28 km) | ✓ yes | Public domain (US Government work) |
| NSW Beachwatch (NSW Government) | State of the Beaches - Beach Suitability Grade (api.beachwatch.nsw.gov.au) | latest report | point (monitored site) | ✓ yes | CC BY 4.0 |
| OpenStreetMap | Beaches, lifeguards, wheelchair access, accommodation (via Overpass API) | point | ✓ yes | Open Database License (ODbL) 1.0 | |
| OurAirports | airports.csv | point | ✓ yes | Public domain | |
| Wikimedia Commons | Photographs near each beach (geosearch + Wikidata P18) | ✓ yes | Per file: public domain, CC0, CC BY or CC BY-SA only | ||
| flag-icons | Country flags in SVG (4:3) | vector | ✓ yes | MIT |
Attribution
- Accessible beaches in Portugal: Agência Portuguesa do Ambiente (APA), CC BY 4.0
- Top images: Sentinel-2 cloudless 2016/2017 by EOX IT Services GmbH (contains modified Copernicus Sentinel data 2016/2017), CC BY 4.0, colour-adjusted
- Bathing water quality: European Environment Agency (EEA), CC BY 4.0
- Place data from GeoNames (CC BY 4.0)
- Climate data from NASA POWER
- Sea surface temperature from NOAA OISST v2.1, NOAA/OAR/ESRL PSL
- New South Wales beach grades: NSW Beachwatch, State of New South Wales, CC BY 4.0
- Beach services and accommodation counts © OpenStreetMap contributors (ODbL)
- Airports from OurAirports (public domain)
- Photos from Wikimedia Commons; author and licence under each photo
- Country flags from flag-icons (MIT licence)
Sunshine hours
Sunshine hours are not measured directly. They are derived from measured solar radiation using the Ångström–Prescott relation, the standard method where no sunshine recorder exists.
Rainy days
A rainy day is a day with at least 1 mm of rain, the World Meteorological Organization definition. We count them from NASA POWER daily rainfall for every day from 1991 to 2025.
Beach facts
Water quality is the official classification of the nearest bathing site (within 1 km): from the European Environment Agency in the EU, from SEPA in Scotland and, in New South Wales (Australia), the NSW Government's Beach Suitability Grade, shown with its own name. Accessibility comes from official lists where they exist (Portuguese Environment Agency, GIP Littoral in Nouvelle-Aquitaine) and elsewhere from OpenStreetMap. Lifeguards come from the RNLI in the UK, GIP Littoral in Nouvelle-Aquitaine and OpenStreetMap elsewhere; places to stay from OpenStreetMap, kept by volunteers. When a source says nothing, we say "no information", never "no". Airport distances are in a straight line, from OurAirports.
Images
The image at the top of each beach is the Sentinel-2 cloudless mosaic by EOX IT Services GmbH (contains modified Copernicus Sentinel data 2016/2017, CC BY 4.0), with its colours adjusted. Photos come from Wikimedia Commons, only under licences that allow this use; each shows its author and licence, and our stylised version keeps the same licence.