Reykjavík tide times

Reykjavík sits on the south-western corner of Iceland, fronting the long Faxaflói bay that opens west to the open North Atlantic, with the Reykjanes peninsula running south-west toward the Mid-Atlantic Ridge surface expression at the Bridge Between Continents and the geothermal coast running north toward Akranes. The Old Harbour at the foot of the city is the working fishing port and the launch point for whale-watching trips into the bay. The tide here is the open North Atlantic signal modulated by the shallow shelf around Iceland: cleanly semidiurnal in pattern, two highs and two lows of comparable size each day, twelve and a half hours apart.

5 on neaps. That is a substantial swing for such a high-latitude open-coast position, and the harbour fishing fleet at the Old Harbour reads it for boat-launch windows on the rising flood. The defining seasonal feature is photoperiod — the midnight sun in June produces 21-hour twilight days when the solunar fishing windows extend through what would be night anywhere else, and the December darkness around the winter solstice compresses solunar activity into a four-hour midday window.

Coastal Reykjavík sees the same swing year-round but the shore-walking and intertidal-photography windows shift dramatically with the seasons. The Atlantic puffin colonies at Lundey across the bay (an hour by boat in season), the geothermal beach at Nauthólsvík where hot-spring water mixes with the cold North Atlantic to produce an outdoor swimmable lagoon, the rocky intertidal at Grótta lighthouse on the western tip of the city, the long sand at Sandgerði on the Reykjanes peninsula, and the surf at Þorlákshöfn south of the peninsula all read the table for different windows. The lowest spring lows around new and full moons open the basalt-shelf intertidal at Grótta for hours either side, exposing kelp-forest margins and seabird-feeding zones.

Storm surge from North Atlantic depressions in winter can lift water levels well above predicted; the harmonic predictions on this site assume normal weather. Open-Meteo Marine drives the gridded predictions on this page; for authoritative Icelandic tide data, the Icelandic Coast Guard's Hydrographic Department (Sjómælingar Íslands) publishes the official tide tables and operates the Reykjavík reference gauge.