West Kaua’i

Tonight: Partly cloudy. Lows 70 to 76 near the shore to around 63 above 3000 feet. East winds up to 15 mph.

Wednesday: Sunny. Highs 86 to 91 near the shore to around 78 above 3000 feet. East winds up to 15 mph.

Wednesday Night: Mostly clear. Lows 69 to 76 near the shore to around 63 above 3000 feet. East winds 10 to 15 mph shifting to the northeast after midnight.

South Kaua’i

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Breezy. Scattered showers. Lows around 74. Northeast winds 10 to 20 mph. Chance of rain 40 percent.

Wednesday: Mostly sunny. Breezy. Isolated showers in the morning. Highs 81 to 89. Northeast winds around 20 mph. Chance of rain 20 percent.

Wednesday Night: Breezy. Partly cloudy in the evening, then mostly cloudy with isolated showers after midnight. Lows around 74. Northeast winds 15 to 20 mph. Chance of rain 20 percent.

Kaua’i Mountains

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 66 to 71 in the valleys to around 60 above 4000 feet. East 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 76 to 85 in the valleys to around 68 above 4000 feet. East winds 10 to 20 mph. Chance of rain 40 percent.

Wednesday Night: Breezy. Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows around 68 in the valleys to around 60 above 4000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

North Kaua’i

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Breezy. Scattered showers. Lows 66 to 75. East winds up to 20 mph. Chance of rain 40 percent.

Wednesday: Mostly sunny. Breezy. Isolated showers in the morning. Highs 78 to 89. East winds 10 to 20 mph. Chance of rain 20 percent.

Wednesday Night: Breezy. Partly cloudy with isolated showers. Lows 66 to 75. East winds 10 to 20 mph. Chance of rain 20 percent.

East Kaua’i

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 65 to 76. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Wednesday: Breezy. Partly sunny with isolated showers in the morning, then mostly sunny in the afternoon. Highs 74 to 87. East winds 15 to 20 mph. Chance of rain 20 percent.

Wednesday Night: Breezy. Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 65 to 76. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Detailed Forecast

Update

Improving conditions on Kauai and Oahu have prompted the cancellation of the AIRMET for mountain obscuration. See the aviation section below for more details.

Synopsis

A high pressure system will remain in place north of the Hawaiian Islands through the weekend keeping moderate to locally breezy trade winds into the extended range forecast. A disturbance passing through the islands today will briefly increase shower activity through the morning hours. More stable conditions with limited shower activity returns into Friday. Another upper level disturbance moves over the islands producing a slight increase in shower activity forecast from Friday afternoon through the weekend.

Prev discussion

/ISSUED 338 AM HST Tue Jul 15 2025/ An easterly wave moving through the islands shows up on this mornings satellite imagery as unstable cloud bands moving through the central and western islands. More stable stratocumulus clouds are filling in behind this trough as the ridge builds over the state and we return to more stable weather conditions later today. Local radar imagery shows scattered to numerous shower bands drifting into the windward and mountain slopes of each island on the trade winds. A few of the strongest showers may bring brief showers to the typically drier leeward areas.
After a wet summer morning, expect drier and more stable conditions to develop across the state lasting into Friday, as high pressure will keep a subsidence cap on vertical cloud development. Subtle changes in the island cloud and shower pattern will become less stable from late Friday on into the weekend, as a weak upper level low injects some instability across the Hawaii Region. A slight increase in shower trends are anticipated mainly during the overnight to early morning hours favoring the windward and mountain areas.
Confidence in these shower trends remain moderate at this time, as the strength of the upper low is currently projected to be on the weaker side of the equation. More details will become clearer later this week, as the time period grows closer, and our confidence on island by island shower trends improve.

Aviation

Surface high pressure will remain north of the Hawaii this week, leading to moderate to locally breezy easterly trade winds. A weak low level trough will produce slightly active showers and periods of MVFR ceiling and visibility on windward Kauai and Oahu this morning, with improvement expected from east to west this afternoon. Stable conditions and VFR will prevail elsewhere.
AIRMET Sierra for mountain obscuration has been cancelled for all islands.

Marine

A ridge of high pressure will remain far north of the state throughout the week. Trades should gradually strengthen today. A Small Craft Advisory (SCA) is in effect for the typical windy areas around Maui County and the Big Island starting 6AM this morning. Fresh to locally strong trades will likely persist through most of the week, although we could see winds drop below SCA criteria as a weak trough develops over the western end of the state into the weekend.
Surf along south facing shores should see a small boost over the next few days due to a pair of south and south-southeast swells. A long-period south swell should peak today near summer averages. As this swell declines a reinforcing swell from the south- southeast should fill in later today into Wednesday. This should maintain surf heights through the middle of the week. Surf should gradually decline Thursday into Friday, but another small increase is expected into the weekend as a new long-period southwest swell arrives from the Tasman Sea.
Surf along east facing shores will continue to remain rough and choppy with surf heights getting a slight increase as the trades strengthen. Surf along north facing shores will continue to decline through Wednesday.

Fire weather

Trade winds will remain in the moderate to locally breezy range into the upcoming weekend. After a period of higher humidity levels and elevated shower trends this morning, weather conditions will dry out and become more stable into Friday. Another increase in shower trends may develop from Friday afternoon through the weekend as an upper level disturbance moves over the island chain.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Wednesday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

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