Hilo

Rest Of Tonight: Partly cloudy with scattered showers. Lows 60 to 70 near the shore to 50 to 57 at 4000 feet. Southwest winds up to 10 mph. Chance of rain 50 percent.

Wednesday: Sunny. Scattered showers in the morning. Highs around 83 near the shore to 66 to 72 at 4000 feet. South winds up to 15 mph. Chance of rain 40 percent.

Wednesday Night: Mostly clear. Lows 60 to 70 near the shore to 51 to 57 at 4000 feet. Southwest winds up to 10 mph.

Kona

Rest Of Tonight: Mostly clear. Lows 68 to 74 near the shore to 47 to 52 near 5000 feet. Light winds.

Wednesday: Sunny. Highs 83 to 88 near the shore to around 69 near 5000 feet. Southeast winds up to 10 mph shifting to the southwest in the afternoon.

Wednesday Night: Mostly clear. Lows 69 to 74 near the shore to 47 to 53 near 5000 feet. Southeast winds up to 10 mph.

Waimea

Rest Of Tonight: Partly cloudy with scattered showers. Lows 61 to 70 near the shore to 53 to 61 near 3000 feet. Light winds. Chance of rain 40 percent.

Wednesday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs around 79 near the shore to 70 to 77 near 3000 feet. Light winds. Chance of rain 20 percent.

Wednesday Night: Partly cloudy. Isolated showers in the evening. Lows 61 to 69 near the shore to 53 to 60 near 3000 feet. Light winds. Chance of rain 20 percent.

Kohala

Rest Of Tonight: Partly cloudy with scattered showers. Lows 61 to 70 near the shore to 53 to 61 near 3000 feet. Light winds. Chance of rain 40 percent.

Wednesday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs around 79 near the shore to 70 to 77 near 3000 feet. Light winds. Chance of rain 20 percent.

Wednesday Night: Partly cloudy. Isolated showers in the evening. Lows 61 to 69 near the shore to 53 to 60 near 3000 feet. Light winds. Chance of rain 20 percent.

South Big Island

Rest Of Tonight: Partly cloudy. Isolated showers in the evening. Lows around 73 near the shore to around 53 near 5000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny. Isolated showers in the morning. Highs around 84 near the shore to around 67 near 5000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday Night: Mostly clear. Lows around 74 near the shore to around 53 near 5000 feet. East winds around 10 mph.

Puna

Rest Of Tonight: Partly cloudy with scattered showers. Lows 60 to 70 near the shore to 50 to 57 at 4000 feet. Southwest winds up to 10 mph. Chance of rain 50 percent.

Wednesday: Sunny. Scattered showers in the morning. Highs around 83 near the shore to 66 to 72 at 4000 feet. South winds up to 15 mph. Chance of rain 40 percent.

Wednesday Night: Mostly clear. Lows 60 to 70 near the shore to 51 to 57 at 4000 feet. Southwest winds up to 10 mph.

Waikoloa

Rest Of Tonight: Partly cloudy. Scattered showers in the evening. Lows around 72 near the shore to 49 to 55 above 4000 feet. Light winds. Chance of rain 40 percent.

Wednesday: Mostly sunny. Highs 82 to 87 near the shore to 66 to 71 above 4000 feet. Light winds.

Wednesday Night: Mostly clear. Lows 69 to 74 near the shore to 49 to 54 above 4000 feet. Light winds.

Detailed Forecast

Update

Update marine section to expand Small Craft Advisory in area and time.

Synopsis

An approaching cold front from the northwest, and pre-frontal convergence, will provide focus for showers and thunderstorms that will primarily impact the western islands beginning this evening and lasting though the next several days. Showers could be heavy at times, especially Wednesday evening through Wednesday night. A Flood Watch is now in effect for Niihau, Kauai, and Oahu through 6 PM HST Thursday. High pressure will begin to build back in this weekend, with a drier pattern expected heading into next week. Easterly trade winds will return this weekend as well, reaching locally strong speeds early next week.

Aviation

A cold front will continue to gradually approach Kauai from the northwest, enhancing showers and producing isolated to scattered thunderstorms along its axis. Ahead of the front, moderate to locally breezy southerly winds will bring low clouds and isolated to scattered showers to south facing coasts and slopes, most of which are being funneled across Oahu and the southeast lower slopes of the Big Island this afternoon. Brief MVFR conditions can be expected as these showers pass through.
Overnight, showers and thunderstorms along the frontal boundary will edge closer and may move over Kauai by Wednesday morning. Otherwise, showers will continue streaming across the central part of the state on the southerly flow, with an increasing potential for heavy rain and thunderstorm development into the day on Wednesday. MVFR and even IFR conditions will be possible as these showers and potential thunderstorms move through. The eastern islands of Maui and the Big Island will remain more stable with prevailing VFR conditions for most airfields.
AIRMET Sierra is in effect for tempo mountain obscurations for Oahu, Molokai and Lanai this afternoon and Kauai will likely need to be added later this evening or late tonight.
AIRMET Tango is in effect for tempo moderate turbulence aloft from 140 to FL340 across the islands associated with the subtropical jet stream over the islands. As the jet weakens over the state this evening, this AIRMET will likely be cancelled.

Marine

A cold front just NW of Kauai waters will advance southeastward and stall near Oahu Wednesday night. Moderate to locally strong southerly winds will strengthen over the western half of the state ahead of the front before easing to light to gentle speeds Wednesday night and Thursday. A Small Craft Advisory (SCA) is now in effect for strengthening winds and back to back large WNW and NNW swells building seas to 10 ft tonight with another reinforcement Thursday. Heavy showers and thunderstorms are possible over Kauai and Oahu waters through Thursday. A strong high pressure system will build N of the state Friday allowing light to moderate trades to return and gradually strengthen to moderate to strong speeds Sunday into early next week.
A large, short to medium period WNW swell fills in tonight through Wednesday from a low to the NW. This swell will elevate surf along north and west facing shores to just below the HSA threshold and will be fairly choppy. Seas will build to 10 feet and higher around Kauai and Oahu waters. A large, medium period NNW swell will fill in Wednesday night and peak Thursday right around advisory levels. This swell will keep SCA level seas (10 feet or greater) over the western half of the state and possibly expand windward Maui waters. This swell will gradually fade out through the remainder of the week with small to moderate N and NW swells mixed in through the weekend.
E shores will remain small except where NW-N swell energy wraps through the week. By next week, NE swell could elevate surf along E facing shores and will become more choppy as strong trade winds return. S shore surf will remain choppy as persistent S-SW winds hold through Wednesday, before gradually easing through the second half week and swinging around to the NE.

Prev discussion

/ISSUED 401 PM HST Tue Dec 16 2025/
Regional satellite imagery this afternoon shows a line of showers and thunderstorms ahead of a surface cold front that extends southward across the northwest offshore waters from a low that is currently centered near 33N163W. Radar imagery, GOES Geostationary Lightning Mapper (GLM) data, National Lightning Detection Network (NLDN), and Global Lightning Detection (GLD) data all show that robust thunderstorms are ongoing across the northern offshore waters, and this line of thunderstorms has moved closer to the Hawaiian coastal waters throughout the day as the front approaches from the northwest. Meanwhile, some pre-frontal convergence within southerly flow over the island chain has resulted in some lighter scattered showers moving across the across mainly the western islands throughout the day. Rainfall amounts today have generally been on the lighter side when compared with the past couple of days, with most accumulations less than one quarter of an inch over the past 6 hours.
This evening and tonight, the front will continue its approach from the northwest, and chances for rain and thunderstorms will increase over the western end of the state. Height falls and cooling temperatures aloft will increase instability. Hi-res guidance and latest CAMs show variations of a similar solution- a couple of bands of showers and thunderstorms setting up over or near Kauai County and Oahu. HREF probabilities also highlight the potential for high rainfall rates greater than 0.5 inch per hour within these bands. Periodic showers have the potential to become organized enough to quickly produce 1 to 2 inches of rain in spots. Given this, a new Flood Watch has been issued for Niihau, Kauai, and Oahu. Maui and Hawaii Counties will also receive some rain, but it will be much more limited as showers there will primarily be a result of surface-based convection from lift created by the local diurnal breezes.
The front is expected to stall over the western end of the state, which will result in continued heavy rain and thunder chances through Friday. Instability, low level convergence, and lift appear to be maximized Wednesday evening into Wednesday night, which provides the best window for flooding concerns.
The weakening boundary will begin to lift away from the state on Friday, beginning a drier trend. Global models indicate that low level flow will become more easterly by Saturday. Upper ridging will form over the islands this weekend, and this subsidence will kick off several days of typical trade weather in the days leading up to Christmas. Model guidance is suggesting that a large North Pacific surface high will tighten the pressure gradient enough to strengthen trades back to locally strong speeds early next week.
AVIATION… A cold front will continue to gradually approach Kauai from the northwest, enhancing showers and producing isolated to scattered thunderstorms along its axis. Ahead of the front, moderate to locally breezy southerly winds will bring low clouds and isolated to scattered showers to south facing coasts and slopes, most of which are being funneled across Oahu and the southeast lower slopes of the Big Island this afternoon. Brief MVFR conditions can be expected as these showers pass through.
Overnight, showers and thunderstorms along the frontal boundary will edge closer and may move over Kauai by Wednesday morning. Otherwise, showers will continue streaming across the central part of the state on the southerly flow, with an increasing potential for heavy rain and thunderstorm development into the day on Wednesday. MVFR and even IFR conditions will be possible as these showers and potential thunderstorms move through. The eastern islands of Maui and the Big Island will remain more stable with prevailing VFR conditions for most airfields.
AIRMET Sierra is in effect for tempo mountain obscurations for Oahu, Molokai and Lanai this afternoon and Kauai will likely need to be added later this evening or late tonight.
AIRMET Tango is in effect for tempo moderate turbulence aloft from 140 to FL340 across the islands associated with the subtropical jet stream over the islands. As the jet weakens over the state this evening, this AIRMET will likely be cancelled.
MARINE…
A cold front just NW of Kauai waters will advance southeastward and stall near Oahu Wednesday night. Moderate to locally strong southerly winds will strengthen over the western half of the state ahead of the front before easing to light to gentle speeds Wednesday night and Thursday. A Small Craft Advisory (SCA) is now in effect for strengthening winds and back to back large WNW and NNW swells building seas to 10 ft tonight with another reinforcement Thursday. Heavy showers and thunderstorms are possible over Kauai and Oahu waters through Thursday. A strong high pressure system will build N of the state Friday allowing light to moderate trades to return and gradually strengthen to moderate to strong speeds Sunday into early next week.
A large, short to medium period WNW swell fills in tonight through Wednesday from a low to the NW. This swell will elevate surf along north and west facing shores to just below the HSA threshold and will be fairly choppy. Seas will build to 10 feet and higher around Kauai and Oahu waters. A large, medium period NNW swell will fill in Wednesday night and peak Thursday right around advisory levels. This swell will keep SCA level seas (10 feet or greater) over the western half of the state and possibly expand windward Maui waters. This swell will gradually fade out through the remainder of the week with small to moderate N and NW swells mixed in through the weekend.
E shores will remain small except where NW-N swell energy wraps through the week. By next week, NE swell could elevate surf along E facing shores and will become more choppy as strong trade winds return. S shore surf will remain choppy as persistent S-SW winds hold through Wednesday, before gradually easing through the second half week and swinging around to the NE.

HFO Watches/Warnings/Advisories

Flood Watch through Thursday afternoon for Niihau, Kauai Leeward, Kauai Mountains, Waianae Coast, Oahu North Shore, Olomana, Central Oahu, Waianae Mountains, Kauai North, Kauai East, Kauai South, East Honolulu, Honolulu Metro, Ewa Plain, Koolau Windward, Koolau Leeward.
Small Craft Advisory until 6 AM HST Thursday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Oahu Leeward Waters, Kaiwi Channel.

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Data Courtesy of NOAA.gov