Where the Sun Sets into the Sea: Sea Sunsets and Sunrises through the Year at the Beaches of Britain and Ireland

From which beaches can one watch the Sun set into, or rise out of, the open sea, and on which days of the year? For the 1,717 named coastal beaches of the United Kingdom and Ireland in OpenStreetMap, I place an observer at the water's edge, eye 3 m above the sea, and cast rays every 0.25 degrees across the year's sunrise and sunset bearings, out to 150 km. Within 12 km the sea is OpenStreetMap's coastline rasterised from OpenFreeMap vector tiles at about 20 to 25 m; beyond, land is terrain above sea level. Land blocks the Sun only where it rises above the sea horizon, allowing for the Earth's curvature and refraction. 46.9% of beaches have a sea sunset on at least one day of 2026, 40.9% a sea sunrise, 8.9% both, and 21.0% neither; 52 beaches, 43 of them in Cornwall, have a sea sunset every day. Sea views are commoner in winter than in summer (349 against 303 beaches for sunsets, 405 against 231 for sunrises on the solstices). Wales has the highest share of sea-sunset beaches (67%). Islands hide the Sun on some days from 303 beaches at sunset and 179 at sunrise: the Isle of Wight and Mull from the most beaches (31 each), Arran from Troon on 134 days, Lundy from Woolacombe on 26.

Interactive version: https://maps.tristanhotham.com/sea-sunsets/. Data and code: https://github.com/Tristan-Hotham/sea-sunsets. Blog post: https://blog.tristanhotham.com/2026/10/31/sea-sunsets/.

Sources: OpenStreetMap contributors (ODbL) via QLever and OpenFreeMap vector tiles; AWS Terrain Tiles; Natural Earth. Derived data under the ODbL; text and figures CC BY 4.0; code MIT.