CatchWindow fishing intelligence

Kahului, Kahului Harbor, HI Daily Water Report — September 4, 2026

Kahului Harbor favors divers, sailors, and surfers today; small boats, kayaks, and rods are working against a stiff east-northeast breeze rather than with it. Diving leads at 8.7, sailing 8.2, and surfing 7.9. Boating and kayaking sit at 5.9, fishing at 5.3, wildlife at 4.9. Those are suitability scores, not safety declarations. The day’s driver is wind. A representative 17 knots from the east-northeast, ranging 9.0 to 17.6, with a 34-knot gust forecast at noon, is a clear step up from the 15 knots reconstructed for yesterday and the 9-to-12-knot stretch earlier in the week. That is why boating and fishing have slipped from the mid-to-high 7s of September 1–2, even with pressure steady near 1011 hPa. Waves stay modest at 1.0 to 1.1 meters, about 10 seconds, with a meter of south swell; the calmest reading is near midnight at 1 meter. Wind waves are negligible and current is slack. Marine SST is 26.6 C, a tenth or two above average. Anyone in a small boat or kayak wants the lighter end of that wind range and a wide berth around midday. Sailors get the inverse: usable breeze, meter-class seas, and heavy cloud (93 percent). Surfing’s 7.9 is more period than size. Divers still score well on modest waves, available clarity inputs, and warm water, even if 8.7 is a tick below the 9-plus run since late August. A rain window is flagged through 11:00, but representative precipitation is zero. Air runs 25 to 28 C; atmospheric visibility is about 48 kilometers, which is not underwater visibility. UV is 8.6. High tide is 0.66 m at 10:24 after a 0.07 m low at 00:36. Solunar majors bookend sunrise and sunset, but fishing’s modest score already includes that timing with wind and tide. Winds ease over the next few days while rain chances stay high through the 8th. Waves hold near a meter on the 5th and 6th, then jump to 1.4–2.8 m on the 7th and 1.5–2.9 m on the 8th before easing. Best bet: dive or sail in the morning, and be off the water before that noon gust tries to edit the day.