Haikou tide times

Haikou is Hainan's provincial capital, positioned on the island's north coast at the mouth of the Nandu River where it opens into Hainan Strait. The tidal regime here is mixed semidiurnal: two highs and two lows per day with noticeable inequality between consecutive highs. Spring range is around 1.2 m, slightly lower than the south coast at Sanya — the northern shelf geometry moderates the tidal signal somewhat. The tidal window opens modestly. At low water springs, broad sandy shallows and mudflats extend across the inner bay; at high water springs, the shoreline tightens against the mangrove fringe.

Hainan Strait is the most significant tidal feature in Haikou's immediate geography. This 30 km channel separating Hainan from Guangdong on the mainland runs the ferry service to Hai'an (crossing time approximately 1.5 hours). Tidal current in the strait runs east-west, strengthening on the mid-flood and mid-ebb. In strong northeast monsoon conditions (October through February), opposing wind-against-ebb creates a short, steep chop in the western approaches. Ferry operators manage this routinely, but passengers who are prone to seasickness should note that crossings in a northeast gale combined with an ebbing tide are the roughest conditions of the year.

Meilan International Mangrove Wetland Park occupies the eastern shore of Haidian Island, the low-lying island connected to central Haikou by bridge. At high tide, the mangrove roots are submerged and the park's boardwalk gives you a view directly into the canopy from water level. At low tide, the pneumatophores (breathing roots) are exposed and the inter-tidal mud is active with mudskippers, fiddler crabs, and wading birds — grey heron, little egret, and black-faced spoonbill in winter. The birdwatching is best two hours before and one hour after low water.

The volcanic rock coast west of the old town — marketed locally as the Haikou Lava Park — is Hainan's most unusual intertidal geology. Basalt from ancient eruptions forms irregular tide pools that hold sea urchins, chitons, and small reef fish through the tidal cycle. The pools are most accessible and most interesting at low tide, when the full basalt platform is exposed. High water covers the platform entirely; the water is clear enough for wading at mid-tide but the uneven rock makes non-slip footwear essential at all stages.

The grey mullet and snapper fishing off Haikou's rocky headlands follows a straightforward pattern: the last two hours of the ebb concentrate bait fish in the gullies between the basalt stacks, drawing predators. Shore anglers work the tide-change windows — from about 90 minutes before low water to 90 minutes after — as the most reliable feeding periods. Squid jigging from the pier at Xiuying Harbour is productive after dark on the high-water slack, when squid move inshore to feed around the lights.

Haidian Island's west-facing beach is the main family swimming spot in Haikou. The bottom gradient is very gentle and the 1 m depth contour sits roughly 60 m offshore at low tide, giving small children an extensive paddling zone. Longshore current is generally weak inside the island's sheltering geometry. The water temperature at Haikou runs cooler than Sanya by 1–2°C in winter — around 20–21°C in January — which is the main reason most international visitors head south to the resort coast.

The inner harbour at Haikou is industrial and not suitable for recreational water contact, but the breakwater on the eastern mole is a popular cast-net and rod-fishing platform. Access to the breakwater is tide-independent; the fishing is best on the flood, when mackerel and small trevally follow bait fish into the harbour mouth.

For photographers, the combination of the old volcanic rock coast and the mangroves gives two very different intertidal landscapes within 15 minutes of each other. The lava park at golden hour, with tide receding and the basalt pools reflecting the sky, is the signature shot.

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