
Surf Forecasts:
Kahalu'u surf forecast from 15 Jul 2026:
- Best quality surf: Thursday 16 Jul, 8AM (local time) - 3ft (0.9m), 15s period, WNW swell with glassy winds.
- Most powerful swell: Monday 20 Jul, 8AM (local time) - 3ft (0.9m), 16s period, S swell with 412 kJ wave energy.
- Next surfable swell (1★+): Wednesday 15 Jul, 5PM (local time) - 2.5ft (0.8m), 16s period with WNW swell.
Best Forecast Surf Conditions for Kahalu'u this week:
The surf forecast for Kahalu'u over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Wednesday (Jul 15) at 5PM. The primary swell is predicted to be 0.8m and 16s period with a secondary swell of 0.5m and 12s. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Kahalu'u in the next 16 days are 0.9m 16s and forecast to arrive on Monday (Jul 20) at 8AM. Winds are predicted to be glassy at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.5m 17s period and expected on Monday (Jul 20) at 2AM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 5PM (Wed 15th Jul) | 2.5ft (0.8m) 16s |
| Best Surf | 8AM (Thu 16th Jul) | 3ft (0.9m) 15s |
| Most Powerful | 8AM (Mon 20th Jul) | 3ft (0.9m) 16s |
Table - best surf conditions forecast for Kahalu'u over the next 16 days.
The Lowdown
Alright, Rusty here. Let’s look at what’s happening at Kahalu'u over the next couple of weeks. This is a reef break on the Big Island, and it’s a beginner-friendly spot that’s very consistent. The water is sitting at 81°, which is about a degree warmer than normal for this time of year – that’s nice.
Right now, things are off to a quiet start. There’s small surf around 3 ft from the west, but the wind is onshore and the energy is just moderate (506). It looks better on Wednesday afternoon when the wind goes cross-off and the conditions clean up nicely. That afternoon has good surf conditions, so if you’re around, get in the water then. Thursday through Sunday is looking pretty average. We’ve got small swells up to 2 ft, but the wind is mostly cross-onshore or onshore, keeping the surface choppy. The energy levels stay moderate (401–429 range), but it’s nothing special. Saturday morning is a dud with poor surf – don’t bother.
Monday the 20th afternoon might be the first real shout. The swell edges up to 3 ft from the south, with cross-off wind and clean conditions. That’s a window to paddle out for some fun, easy waves. Tuesday looks so-so again, but then something interesting shows up.
Wednesday the 22nd gets a big pulse of long-period energy from the SSW. The swell is only 2 ft, but the period jumps to 24 seconds, pushing the combined energy way up to 720 – that’s strong energy considering the height. These are very lanky, clean groundswell lines, perfect for this reef setup. The wind is cross-onshore though, so the surface won’t be perfect, but that deep-water energy will wrap in nicely.
Then Thursday the 23rd afternoon is my pick of the entire forecast. You’ll get 3 ft from the SSW at a 20-second period, but here’s the kicker: glassy wind. The energy is pumping at 701, and the conditions are described as very good surf. That’s going to be clean, lined-up, and fun for a beginner spot.
Friday the 24th afternoon is another strong one. Same 3 ft SSW swell, 18-second period, with cross-off wind and very good conditions. The energy is high (721). That’s two afternoons in a row worth marking on your calendar.
The following week sees the swell holding around 3 ft to 3 ft, mostly from the SSW, with moderate energy (672–738 range), but the wind stays mostly cross-onshore or cross-shore. Nothing terrible, but not as clean as those two standout afternoons. By the 29th and 30th, the surf fades. Energy drops below 100, and it’s poor conditions. That run of a few days without good surf is a normal way for the window to end.
So, if you’re after the best: Make plans for Thursday the 23rd afternoon or Friday the 24th afternoon. Glassy or cross-off wind, solid energy, and clean lines at Kahalu'u. Crowds can show up here sometimes, so expect company, but the waves will be worth it.
Rusty.
Short Range ForecastMostly dry. Warm (max 27°C on Thu morning, min 25°C on Wed morning). Wind will be generally light. | Days 4-6 Weather SummaryLight rain (total 6mm), mostly falling on Sat night. Warm (max 27°C on Sat morning, min 25°C on Sat night). Wind will be generally light. | ||||||||||||||||||||
Wednesday 15 | Thursday 16 | Friday 17 | Saturday 18 | Sunday 19 | Monday 20 | Tuesday 21 | |||||||||||||||
AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | |
Swell Height Map | |||||||||||||||||||||
Wave Height (m) Direction Period (s) | W 16 | WNW 16 | WNW 15 | WNW 15 | W 15 | W 14 | W 14 | W 14 | SSW 14 | SSW 14 | SSW 14 | SSW 12 | S 19 | S 18 | S 14 | S 16 | S 15 | S 15 | S 14 | S 14 | SSW 26 |
Wave Graph | |||||||||||||||||||||
314 | 320 | 380 | 292 | 272 | 268 | 203 | 198 | 163 | 160 | 158 | 117 | 110 | 155 | 57 | 326 | 357 | 272 | 316 | 184 | 222 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | cross-off | cross-on | cross-on | on | glassy | cross-on | cross-on | glassy | on | on | on | cross-on | cross | cross-on | cross-on | cross-off | cross | cross-on | cross | cross-on |
High Tide | 5:02PM0.91m | 5:16AM0.40m | 5:40PM0.85m | 6:10AM0.44m | 6:15PM0.76m | 7:07AM0.48m | 6:47PM0.67m | 8:10AM0.52m | 7:17PM0.57m | 9:18AM0.55m | 7:44PM0.48m | 10:31AM0.59m | 8:10PM0.40m | ||||||||
Low Tide | 9:50AM0.01m | 00:04AM0.09m | 10:39AM0.07m | 00:38AM0.09m | 11:29AM0.14m | 1:10AM0.09m | 12:23PM0.22m | 1:41AM0.10m | 1:28PM0.31m | 2:13AM0.11m | 2:57PM0.37m | 2:47AM0.13m | 5:17PM0.38m | 3:28AM0.14m | |||||||
5:52 | — | — | 5:54 | — | — | 5:54 | — | — | 5:54 | — | — | 5:54 | — | — | 5:54 | — | — | 5:54 | — | — | |
— | 7:05 | — | — | 7:05 | — | — | 7:05 | — | — | 7:05 | — | — | 7:04 | — | — | 7:04 | — | — | 7:04 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | 2 | — | — | 4 | — | — | — | — | — | — |
Temp °C | 26 | 26 | 26 | 27 | 27 | 26 | 27 | 27 | 26 | 27 | 27 | 26 | 27 | 26 | 26 | 27 | 27 | 26 | 27 | 27 | 26 |
Feels °C | 27 | 28 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 30 | 30 | 28 | 29 | 29 | 29 | 29 | 29 | 28 | 29 |
Swell 1 Height (m) Direction Period (s) | W 16 | WNW 16 | WNW 15 | WNW 15 | W 15 | W 14 | W 14 | SSW 16 | SSW 14 | SSW 14 | SSW 14 | SSW 12 | SSW 13 | SSW 13 | S 17 | S 16 | S 15 | S 15 | S 14 | S 14 | SSW 11 |
314 | 320 | 380 | 292 | 272 | 268 | 203 | 196 | 163 | 160 | 158 | 117 | 96 | 93 | 140 | 326 | 357 | 272 | 316 | 184 | 91 | |
Swell 2 Height (m) Direction Period (s) | SSW 13 | SW 12 | SW 16 | SW 12 | SW 13 | SW 12 | S 16 | W 14 | W 14 | W 13 | W 13 | W 13 | WNW 12 | S 18 | SSW 11 | SSW 11 | SW 18 | SSW 13 | SSW 12 | SSW 11 | S 13 |
113 | 73 | 201 | 73 | 80 | 68 | 131 | 198 | 138 | 89 | 87 | 87 | 50 | 155 | 40 | 46 | 50 | 66 | 30 | 98 | 128 | |
Swell 3 Height (m) Direction Period (s) | SW 18 | SW 15 | SSW 15 | SW 16 | SSW 17 | SSW 17 | SW 12 | SW 12 | SW 8 | SSW 15 | S 21 | S 15 | S 19 | WNW 12 | S 14 | WNW 12 | WNW 12 | SW 16 | SW 17 | SW 16 | SSW 26 |
79 | 56 | 78 | 130 | 101 | 97 | 67 | 35 | 9 | 21 | 9 | 17 | 110 | 49 | 57 | 27 | 26 | 69 | 74 | 67 | 222 | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | W 7 | SW 7 | — | — | — | — | — | — | W 8 | — | — | — |
— | — | — | — | — | — | — | — | — | 4 | 8 | — | — | — | — | — | — | 1 | — | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 54 | 0 | 6 | 51 | 31 | 0 | 49 | 31 | 0 | 51 | 42 | 12 | 125 | 13 | 89 | 75 | 0 | 2 | 123 | 13 | 6 |
Best forecast wave conditions in Big Island | |||||||||||||||||||||
Best forecast wave conditions in United States | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)
Wind Speed (km/h)
Information about the Kahalu'u Surf forecast
The above surf forecast table for Kahalu'u provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Kahalu'u can be found by selecting the local surf guide option on the grey menu. Our Kahalu'u surf forecast is unique since it includes wave energy (power) that defines the real feel of the surf rather than just the height or the period. If you surf the same spot (Kahalu'u) regularly then make a mental note of the wave energy from the surf forecast table each time you go. Very soon you may start to choose your surf days based on the wave energy alone combined with our forecast of favourable offshore wind conditions. Our star ratings will help here and of course you will also find the usual wave height and period predictions on our surf forecasts as well as a full break down of the swell components under our advanced users option (to reveal that, click the little Einstein character under the tide times).
Further information to help with frequently asked questions about our surf forecast for Kahalu'u may be found under the help tab on the top menu and also by moving your mouse over the question marks on the surf forecast table itself. Please always bear in mind that the forecast is for near-shore open water and local factors at each surf break influence the actual breaking wave height, such as the beach / reef profile, water depths offshore and shelter.
Kahalu'u is 93 km (58 miles) from Hilo. If you plan a vacation in Big Island, look for hotels and other accommodation in Hilo. Hilo has rooms for a wide range of budgets as well as car hire and transport links.










