El Nino Watch
Wave height and sea surface temperature at the sea cell nearest to each place (Open-Meteo marine model). Inland places have none.
Ocean
For each place on the Places page the app asks the Open-Meteo marine model for the nearest sea grid cell and keeps its wave height (m) and sea surface temperature (°C), recent days and forecast. Places far from the sea (Gorokhovets, for example) get no sea cell and are shown as "inland".
The distance to the chosen cell is a rough indication: the model grid is coarse (about 5-25 km), so a sheltered bay can be calmer than its cell.
Waves below 1.25 m are moderate; 2 m and more stop small boats and fast ferries in the Gulf of Thailand; 3 m and more usually stop the car ferries. Values after today are forecasts.
For an island (Maenam) the sea decides whether ferries and supplies run; on the mainland it matters for coastal flooding and fishing only.