West Kaua’i

Tonight: Mostly clear. Breezy. Isolated showers after midnight. Lows around 64 near the shore to around 55 above 3000 feet. Northeast winds up to 20 mph becoming 10 to 15 mph after midnight. Chance of rain 20 percent.

Wednesday: Sunny and breezy. Isolated showers in the morning. Highs around 81 near the shore to around 69 above 3000 feet. Northeast winds up to 20 mph. Chance of rain 20 percent.

Wednesday Night: Mostly clear. Isolated showers after midnight. Lows around 66 near the shore to around 56 above 3000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

South Kaua’i

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows around 65. Northeast winds 10 to 25 mph. Chance of rain 50 percent.

Wednesday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 75 to 82. Northeast winds 10 to 20 mph increasing to 20 to 25 mph in the afternoon. Chance of rain 50 percent.

Wednesday Night: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows around 65. Northeast winds 10 to 20 mph. Chance of rain 40 percent.

Kaua’i Mountains

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 57 to 63 in the valleys to around 52 above 4000 feet. East winds up to 25 mph. Chance of rain 50 percent.

Wednesday: Breezy. Partly sunny with numerous showers in the morning, then mostly sunny with scattered showers in the afternoon. Highs 70 to 76 in the valleys to around 59 above 4000 feet. East winds up to 20 mph. Chance of rain 70 percent.

Wednesday Night: Breezy. Mostly cloudy with scattered showers. Lows 58 to 64 in the valleys to around 53 above 4000 feet. East winds up to 20 mph. Chance of rain 50 percent.

North Kaua’i

Tonight: Breezy. Partly cloudy with scattered showers. Lows 58 to 67. East winds 10 to 20 mph. Chance of rain 50 percent.

Wednesday: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 72 to 81. East winds up to 15 mph. Chance of rain 50 percent.

Wednesday Night: Partly cloudy with scattered showers. Lows 59 to 67. East winds up to 15 mph. Chance of rain 50 percent.

East Kaua’i

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 58 to 70. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Wednesday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 68 to 79. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Wednesday Night: Partly cloudy in the evening then becoming mostly cloudy. Scattered showers. Lows 60 to 70. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Moderate to locally breezy trades will taper off Wednesday and Thursday becoming light and variable by this weekend. Shower activity will be kept to a minimum with just a few windward and mauka clouds and showers through the end of the week.

Short term update

Issued at 815 PM HST Tue Mar 31 2026
The latest forecast remains on track, therefore requires no amendments this evening. Light showers persist across the Hawaiian Islands with many locations limited to a few hundredths of an inch, if any. Otherwise, some cloud build up across the state, namely along windward areas in association with trades activity. The highlight of the evening is that trades are expected to begin easing in strength as the surface high weakens. This should be well represented in this morning's forecast and discussion.

Prev discussion

A stationary upper low persists northeast of the state. At the surface, a 1028 mb surface high is centered far north of Hawaii driving fresh to locally strong trade winds across the area. Moisture levels are below average, with precipitable waters running around 0.9 inches, so while some instability from the upper low and orographic lifting will bring a few windward showers tonight, rainfall amounts will be limited by the moisture levels. Expect another cool night lows in the low to mid 60s and dew points in the upper 50s.
Looking ahead, trades will begin to ease Wednesday into Thursday as the surface high weakens and shifts eastward with a surface trough developing east of Hawaii. This feature will weaken the trade wind flow to moderate over the islands through the rest of the week. Rainfall will be limited to occasional small batches of moisture moving in from the east by the trades.
A front will approach from the west during the first half of next week. Winds will weaken, shift southeasterly, then south, while a pre-frontal convergence band drags tropical moisture up over the islands. Still significant model differences in the long-range GFS and ECMWF for the synoptic setup, but something to watch out for mid to late next week.

Aviation

Issued at 815 PM HST Tue Mar 31 2026
Moderate to locally breezy trade winds will continue into tonight. Winds will slightly weaken tomorrow. Isolated showers are possible tonight along windward and mauka areas which may lower ceilings and visibilities to MVFR at times. Otherwise, VFR conditions will prevail.
No AIRMET's are currently in effect.

Marine

A 1030 mb high pressure north of Hawaii will elongate and shift eastward through the week, causing trade winds to gradually diminish. The Small Craft Advisory for fresh to locally strong trade winds remains in effect across all Hawaiian waters through Wednesday morning. By that point, a weakening pressure gradient means that strong trade winds are expected to be limited to favored channels only. Winds become moderate to fresh northeasterly for the majority of the waters by this weekend.
Moderate north and east-facing shore surf continues to be generated by a short period north-northeast (020 degree) swell which will gradually diminish tonight and Wednesday as it veers northeast. Shores better exposed to this NNE swell will experience decent wind wave chop generated by solid moderate trades.
Surf along west-facing shores will remain dominated by wrap around from the north-northeasterly swell and will gradually diminish in kind through the week. The next small, medium-period northwest and west-northwest swells arrive this weekend to bring a small bump in surf for west-facing shores. Along south-facing shores, expect continued impulses to sustain small surf through the week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Wednesday for Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters, Big Island Windward Waters, Kaiwi Channel, Kauai Channel, Kauai Leeward Waters, Kauai Northwest Waters, Kauai Windward Waters, Maalaea Bay, Maui County Leeward Waters, Maui County Windward Waters, Oahu Leeward Waters, Oahu Windward Waters, Pailolo Channel.

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Data Courtesy of NOAA.gov