Surf Forecasts:
Waimanalo surf forecast from 18 Aug 2026:
- Most powerful swell: Monday 24 Aug, 8PM (local time) - 10ft (3.0m), 8s period, ENE swell with 1,003 kJ wave energy.
Best Forecast Surf Conditions for Waimanalo this week:
The most powerful waves expected at Waimanalo in the next 16 days are 3.0m 8s and forecast to arrive on Monday (Aug 24) at 8PM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.5m 12s period and expected on Tuesday (Aug 25) at 8AM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 8PM (Mon 24th Aug) | 10ft (3.0m) 8s |
Table - best surf conditions forecast for Waimanalo over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s take a look at what’s on offer for the stretch ahead. I won’t sugar coat it – this is a tough run for Waimanalo. The whole forecast window is littered with onshore and cross-onshore winds, mainly from the ENE, with very little let-up. The swell energy gets large, but it’s coming straight from the east-northeast and the wind is out of the same direction, which isn’t ideal.
We start off the run on Tuesday, 18th August, up through the weekend and into the following week. There’s nothing surfable for the first week. The guidance rates Waimanalo as suitable for beginners and it’s fairly consistent, but the finder data keeps throwing up “poor surf conditions” and scores of zero. The water temp is sitting at 80°F, right around average for this time of year – no real anomaly to mention there.
The wind stays moderate to fresh from the ENE, sometimes hitting 28 mph around the 24th and 25th. Even though the combined swell energy gets up to 816 towards the 24th afternoon, it’s an onshore mess with short period wind swell of just 6 to 8 seconds. That’s not the kind of energy that makes for good waves here.
The real low point comes around the 30th of August and 31st, with swell heights pushing up over 10 ft and combined energy reaching strong levels up to 1552. But again, the wind is lunging straight on or cross-onshore. Those waves will be big, but they’ll be a blown-out, lumpy battle. Not a session for the average punter.
There’s a flicker of hope slipping into the first two days of September. On Tuesday morning the 1st, the conditions shift slightly with lighter cross-onshore E winds at 9 mph, and the wave comment changes to “marginal surf forecast or questionable tide conditions” with a score of 1. Then on Wednesday morning the 2nd, it looks a touch better – wind from the E at 6 mph, a light cross-onshore, and the tide might line up just enough to give you a 2/10 session. At that point, wave heights are still around 8 ft, with energy at 680. The swell direction is east and the period ticks up to 8 seconds. It’s not going to be amazing, but it will be the cleanest you’ll find across the entire 16-day window. Keep your expectations low and you might snag a couple of lumpy ones out the back.
Otherwise, this is a long stretch where kite gear might get a better workout than a surfboard. The swell is there, but the wind is the boss, and it’s not playing nice. If you’re desperate, watch the 2nd of September, but don’t plan a trip around it.
Rusty
Short Range ForecastMostly dry. Warm (max 26°C on Wed afternoon, min 24°C on Tue night). Wind will be generally light. | Days 4-6 Weather SummaryMostly dry. Warm (max 27°C on Fri afternoon, min 25°C on Fri morning). Winds increasing (light winds from the ESE on Fri morning, fresh winds from the ENE by Sun night). | ||||||||||||||||||||
Tuesday 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | |||||||||||||||
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) | ENE 7 | ENE 7 | ENE 8 | E 8 | E 8 | E 8 | E 8 | E 8 | E 7 | NNE 7 | E 7 | ENE 7 | E 6 | E 6 | E 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 | ENE 8 |
Wave Graph | |||||||||||||||||||||
149 | 136 | 143 | 89 | 84 | 84 | 58 | 55 | 70 | 38 | 61 | 141 | 188 | 259 | 360 | 419 | 336 | 397 | 542 | 800 | 893 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | on | on | on | on | on | on | on | on | cross-on | cross-on | on | cross-on | on | on | on | on | on | on | on | cross-on |
High Tide | 8:02AM0.45m | 4:17PM0.43m | 10:23AM0.47m | 11:48AM0.51m | 12:32PM0.55m | 1:04PM0.58m | 10:27PM0.27m | 1:31PM0.61m | 11:46PM0.30m | 1:55PM0.63m | 00:27AM0.33m | ||||||||||
Low Tide | 12:27PM0.33m | 00:26AM0.08m | 1:15AM0.09m | 2:41AM0.09m | 4:16AM0.08m | 9:18PM0.23m | 5:19AM0.05m | 8:24PM0.22m | 6:03AM0.02m | 8:21PM0.21m | |||||||||||
6:09 | — | — | 6:09 | — | — | 6:09 | — | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | |
— | 6:58 | — | — | 6:58 | — | — | 6:57 | — | — | 6:55 | — | — | 6:54 | — | — | 6:53 | — | — | 6:53 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 25 | 25 | 25 | 25 | 26 | 25 | 25 | 26 | 26 | 26 | 27 | 26 | 26 | 26 | 25 | 25 | 25 | 25 | 25 | 25 | 25 |
Feels °C | 24 | 24 | 25 | 26 | 26 | 25 | 27 | 28 | 29 | 30 | 30 | 28 | 26 | 25 | 24 | 23 | 23 | 23 | 22 | 21 | 21 |
Swell 1 Height (m) Direction Period (s) | S 13 | S 13 | S 13 | E 8 | E 8 | E 8 | E 8 | NE 7 | E 7 | NNE 7 | NE 7 | SSW 16 | SSE 15 | WNW 13 | NW 12 | NW 11 | NW 10 | ESE 9 | SSE 12 | SSE 12 | SSE 12 |
54 | 30 | 29 | 89 | 84 | 84 | 58 | 47 | 70 | 38 | 44 | 50 | 42 | 18 | 38 | 30 | 27 | 86 | 29 | 28 | 46 | |
Swell 2 Height (m) Direction Period (s) | SW 17 | SW 18 | NNE 7 | NE 6 | S 12 | NE 6 | NE 6 | E 8 | NNE 7 | ENE 7 | ESE 8 | S 13 | SSW 16 | SSW 16 | SSE 14 | SSE 13 | SSE 13 | SSE 13 | NW 10 | NW 10 | NW 10 |
11 | 12 | 5 | 43 | 11 | 49 | 42 | 55 | 40 | 31 | 7 | 14 | 26 | 25 | 41 | 35 | 34 | 33 | 16 | 16 | 17 | |
Swell 3 Height (m) Direction Period (s) | N 7 | W 13 | SW 18 | S 12 | SSE 9 | S 12 | SSW 18 | SSW 18 | SSW 17 | E 7 | SSW 16 | SSE 16 | NW 15 | S 12 | SSW 16 | SSW 16 | SSW 15 | NW 10 | SSW 14 | SSW 13 | SSW 13 |
1 | 3 | 12 | 11 | 8 | 11 | 31 | 30 | 27 | 24 | 25 | 24 | 8 | 12 | 24 | 24 | 22 | 17 | 19 | 18 | 16 | |
Wind waves Height (m) Direction Period (s) | ENE 7 | ENE 7 | ENE 8 | — | NE 6 | — | — | — | — | — | E 7 | ENE 7 | E 6 | E 6 | E 7 | ENE 7 | ENE 7 | ENE 7 | ENE 7 | ENE 8 | ENE 8 |
149 | 136 | 143 | — | 39 | — | — | — | — | — | 61 | 141 | 188 | 259 | 360 | 419 | 336 | 397 | 542 | 800 | 893 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 17 | 15 | 15 | 15 | 15 | 15 | 14 | 9 | 5 | 5 | 5 | 15 | 44 | 50 | 46 | 50 | 117 | 50 | 56 | 117 | 116 |
Best forecast wave conditions in Oahu | |||||||||||||||||||||
Best forecast wave conditions in United States | |||||||||||||||||||||
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Information about the Waimanalo Surf forecast
The above surf forecast table for Waimanalo provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Waimanalo can be found by selecting the local surf guide option on the grey menu. Our Waimanalo 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 (Waimanalo) 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 Waimanalo 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.
Waimanalo is 7 km (4 miles) from Kailua. If you plan a vacation in Oahu, look for hotels and other accommodation in Kailua. Kailua has rooms for a wide range of budgets as well as car hire and transport links.











