Burnham-on-Sea tide times

Burnham-on-Sea has one of the largest tidal ranges of any beach in the world. Spring range here is approximately 12.0 m — the figure is not a typo, and it is not a maximum-ever reading. It is the mean spring tidal range, recorded consistently at the mouth of the River Parrett where it meets the Bristol Channel. The mechanism is the same as all Bristol Channel sites: a natural funnel geometry that amplifies the Atlantic tidal wave as it travels east, and a resonant period that happens to match the semidiurnal tidal frequency closely. At Burnham the land is almost completely flat, so a 12 m vertical change in water level translates into a horizontal retreat of more than 2 km across the beach and sand flats.

At high water springs, Burnham-on-Sea beach is a narrow strip of sand backed by the famous low lighthouse (the lighthouse is built on stilts precisely because the beach floods this far). Within 3 hours, the sea has retreated far enough that the lighthouse stands surrounded by dry sand, and within 6 hours — at the following low water — the waterline is over 2 km away. The flats exposed between the town and the waterline are primarily fine, level sand in the middle section and saltier, silty ground near the River Parrett channel.

The flood tide across these flats is the feature that requires explicit safety management. The Bristol Channel tide does not creep in — it advances steadily across the gradient-free surface, and in the final quarter of the flood the rate of advance over the sand can reach 16 km/h in exceptional conditions, according to Somerset Council's coastal safety publications. Practically, this means a person standing at the waterline at low water has roughly 6 hours before the sea reaches their starting position. But a person who walks out to the waterline and waits 2 hours before starting to return is not safe — the tide is now a third of its cycle into the flood and moving faster than it was at low water. The rule at Burnham is: be moving back toward the town before the flood starts, not after you see the water coming.

The River Parrett enters the Bristol Channel just south of Burnham-on-Sea, and the spring flood produces a tidal bore on the river. The Parrett bore is not the Severn Bore's drama — it is typically 0.3 to 0.6 m high on the largest springs — but it is clearly visible from the riverbank at Burnham and from the path toward Combwich. The bore arrives on the flood tide approximately 30 to 45 minutes after Burnham high water in reverse — it travels upstream, so you need to be positioned upstream of the river mouth before the flood peaks. Check the bore timetable published by the Parrett Bore Society.

Berrow Dunes, 2 km north of Burnham, is a SSSI sand dune and beach system immediately north of the town. The dunes stabilise the northern approach to the beach; the foreshore there is very similar in tidal character to Burnham itself — same 12 m spring range, same retreat distance. The dunes are protected habitat and should not be climbed or crossed at marked points.

For anglers, the bass fishing on the Burnham flood tide is serious. Bass follow the flood edge across the sand flat from the first of the tide; the fish are often visible as bow waves and splashes at the waterline as they chase whitebait and sandeel. Lure fishing from the waterline on the first two hours of the flood is productive. The River Parrett channel holds mullet from April through October. Eels are a traditional Burnham catch from the Parrett in summer.

The SSSI designation at Burnham-on-Sea and Berrow covers internationally important estuarine bird habitat: dunlin, knot, grey plover, and black-tailed godwit in winter; ringed plover nesting in the dunes in summer. Low water at a morning spring tide from October through March brings the highest wader concentrations onto the flats.

Tidal predictions here use the Open-Meteo Marine gridded model (±45 minutes on timing, ±0.3 m on height). Not for navigation.