Hilo tide times

Hilo sits on the rainy side of Hawai'i Island, where the Wailuku and Wailoa rivers drain the Mauna Kea slopes into a bay that faces northeast — directly into the North Pacific swell window. The tidal pattern is mixed semidiurnal: two unequal highs and lows each day. Mean tidal range is around 0.6 metres, with spring tides reaching 0.8 m. The astronomical tide is modest, but Hilo Bay's history with tsunamis is a reminder that extraordinary water level events are not just theoretical here.

The two tsunamis of 1946 and 1960 destroyed the original downtown waterfront. The rebuilt town sits set back from the bay, and the former waterfront area — now Wailoa River State Park — is deliberately left as open green space. The civic memory shapes how locals think about ocean conditions; tide plus swell plus event is always the mental model.

Surf at Hilo is not what most visitors expect. The northeast exposure catches raw swell in winter; Richardson Ocean Park on the east side of the bay has a rocky entry but delivers consistent waves for bodyboarders and experienced surfers. The bay itself damps swell significantly — inside the bay, conditions are calmer and more suited to kayaking and outrigger canoe training.

Hilo is the departure point for snorkelling and dive charters heading south toward the Kapoho tide pools and the lava coast. Water clarity in the open ocean off the Puna coast is exceptional; visibility routinely exceeds 30 metres. The tidal range is small enough that snorkelling access is practical at most tides, though surge on the lava shelves requires caution — water level can change 0.3 metres in under a minute on exposed lava benches.

Kayaking in Hilo Bay is calm and the route around the breakwater to Coconut Island (Mokuola) is a standard beginner circuit. Outrigger canoe paddling is a deeply embedded local sport; several clubs train in the bay in the early morning before the trade wind fills in. Fishing from the breakwater is productive for papio (juvenile jack crevalle), pua'ama (bonefish), and occasionally bonefish on the flats at Onekahakaha Beach Park.

The Suisan Fish Auction at the Hilo waterfront is one of the few remaining traditional fish auctions in the state — it runs most weekday mornings before dawn. The boats unload catches of ahi, ono, and marlin directly from overnight trips to the deep-water grounds south of the island. Tide depth in the harbour determines access for the deeper-drafted longliners.

Predictions on this page come from Open-Meteo Marine, a gridded global ocean model. Accuracy is typically within plus or minus 45 minutes on timing and 0.2 to 0.3 metres on height — model-derived, not from a local gauge. For authoritative US tide data, consult NOAA CO-OPS at tidesandcurrents.noaa.gov.