Surf Forecasts:
Wanjapu surf forecast from 18 Aug 2026:
- Best quality surf: Wednesday 19 Aug, 8AM (local time) - 7.5ft (2.3m), 19s period, SW swell with cross-offshore winds.
- Most powerful swell: Thursday 20 Aug, 5AM (local time) - 10ft (3.0m), 17s period, SW swell with 4,690 kJ wave energy.
- Next surfable swell (1★+): Wednesday 19 Aug, 8AM (local time) - 7.5ft (2.3m), 19s period with SW swell.
Best Forecast Surf Conditions for Wanjapu this week:
The surf forecast for Wanjapu over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Wednesday (Aug 19) at 8AM. The primary swell is predicted to be 2.3m and 19s period with a secondary swell of 0.6m and 7s. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Wanjapu in the next 16 days are 3.0m 17s and forecast to arrive on Thursday (Aug 20) at 5AM. Winds are predicted to be glassy at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.9m 7s period and expected on Thursday (Aug 20) at 8PM.
| Wave Type | Time (WITA) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 8AM (Wed 19th Aug) | 7.5ft (2.3m) 19s |
| Best Surf | 8AM (Wed 19th Aug) | 7.5ft (2.3m) 19s |
| Most Powerful | 5AM (Thu 20th Aug) | 10ft (3.0m) 17s |
Table - best surf conditions forecast for Wanjapu over the next 16 days.
The Lowdown
Alright folks, let’s get straight into it. The ocean’s got a good-sized SW groundswell pushing through Wanjapu right now, with a long 18-second period, and the water temp is right where it should be for August. The energy is pumping—3473 in the combined swell energy—and we’ve got a light cross-offshore wind putting some real shine on the face. This is a consistent, exposed reef break, so it’s been handling this swell well. It’s an advanced wave, so if you’re not comfortable on a proper reef, maybe watch from the rocks. The standout session is Wednesday morning: 8ft of clean, powerful surf with that offshore breeze grooming it. The afternoon stays strong at 8ft, still clean. That’s the session you don’t want to miss.
Thursday (20 August) pushes up to 10ft in the morning, but the wind swings more cross and it starts to get a bit more unruly. Still plenty of grunt with a 16-second period and energy at 4122, but the surface isn’t as clean. The afternoon backs down to 8ft with a cross-off breeze, but it’s a step down in quality. Friday and Saturday are a bit of a mixed bag—waves hold in the 7ft to 8ft range, but the period eases off and the wind gets more cross or cross-on, putting a bit of chop on the face. Saturday morning gets a bit lumpy with the cross-on wind.
Swell starts to ease into Sunday and Monday, dropping to around 6ft to 7ft, with light winds but still mostly cross or cross-on, so it’s not clean glass. It’s a bit of a grind, to be honest. The energy drops off into the 1700-2400 range, so it’s moderate at best. Then things get quiet. From Tuesday 25 August through the end of the week, we hit a proper lull. The swell really winds down, with Thursday 27 August bottoming out at a tiny 3ft with a super long 20-second period—long waits between sets and not a lot behind them. Energy readings drop way down into the 600-1300 zone. There’s a small bump on Friday 28 August morning with 8ft and a 17-second period, but the wind looks wrong for the reef, with cross-on conditions and poor quality, so it’s not the clean, rippable session we’re after.
Now, looking out to the first week of September—this is the one to circle on the calendar. We’re talking Tuesday 1 September and Wednesday 2 September, which is more than a week out, so treat it as promising but not locked in. The models are hinting at another solid pulse of SW swell, with sizes back up to 8ft to 10ft and periods around 16-17 seconds. Energy readings look strong again, with one hit coming in at 4489. The key is that there are windows on those afternoons where the wind turns cross-offshore and the surf cleans right up. If that happens, it could be as good as this Wednesday, if not better. The days after that see the swell slowly fade and winds get tricky again.
So, bottom line: Wednesday morning is your best bet right now, and keep your fingers crossed for September 1st and 2nd. Otherwise, it’s just average waves for average conditions. Wanjapu is a consistent spot, so it won’t go flat, but it won’t be perfect every day either. Get out there Wednesday.
Rusty.
Short Range ForecastMostly dry. Warm (max 26°C on Wed morning, min 23°C on Wed night). Wind will be generally light. | Days 4-6 Weather SummaryMostly dry. Warm (max 26°C on Sat morning, min 23°C on Sat night). Wind will be generally light. | ||||||||||||||||||||
Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | Tuesday 25 | |||||||||||||||
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) | SW 18 | SW 18 | SW 17 | SW 16 | SW 16 | SW 16 | SW 15 | SW 17 | SW 16 | SSW 16 | SSW 16 | SW 15 | SSW 15 | SW 15 | SW 15 | SSW 15 | SW 16 | SW 15 | SSW 15 | SW 16 | SW 15 |
Wave Graph | |||||||||||||||||||||
3452 | 4091 | 4687 | 4084 | 3334 | 2687 | 2102 | 2893 | 2694 | 2821 | 2472 | 1962 | 1937 | 1597 | 1358 | 2069 | 1531 | 1472 | 1174 | 1715 | 1237 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | cross-off | cross | cross-off | cross-off | cross | cross | cross-off | cross-on | cross | cross-off | cross-on | cross | cross | cross | cross | cross-off | on | cross | cross-off |
High Tide | 1:58PM2.13m | 2:10AM2.58m | 2:29PM1.87m | 2:41AM2.37m | 3:08PM1.61m | 3:22AM2.16m | 5:09PM1.39m | 4:56AM1.98m | 10:23PM1.56m | 7:25AM2.01m | 9:48PM1.77m | 8:39AM2.20m | 10:04PM1.98m | ||||||||
Low Tide | 8:06AM0.57m | 7:46PM0.72m | 8:43AM0.77m | 8:07PM0.93m | 9:30AM0.97m | 8:25PM1.13m | 10:54AM1.14m | 8:29PM1.34m | 2:18PM1.08m | 11:41PM1.56m | 3:12PM0.86m | 2:42AM1.40m | 3:41PM0.66m | 3:26AM1.18m | |||||||
6:13 | — | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:11 | — | — | 6:09 | — | — | 6:09 | — | — | |
— | 6:01 | — | — | 6:01 | — | — | 6:01 | — | — | 6:01 | — | — | 6:01 | — | — | 6:01 | — | — | 6:01 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 26 | 26 | 25 | 25 | 26 | 25 | 25 | 26 | 24 | 25 | 26 | 25 |
Feels °C | 27 | 27 | 27 | 26 | 26 | 26 | 27 | 28 | 26 | 27 | 28 | 26 | 26 | 26 | 26 | 26 | 27 | 23 | 26 | 28 | 26 |
Swell 1 Height (m) Direction Period (s) | SW 18 | SW 18 | SW 17 | SW 16 | SW 16 | SW 16 | SW 15 | SW 17 | SW 16 | SSW 16 | SSW 16 | SW 15 | SSW 15 | SW 15 | SW 15 | SSW 15 | SW 16 | SW 15 | SSW 15 | SW 16 | SW 15 |
3452 | 4091 | 4687 | 4084 | 3334 | 2687 | 2102 | 2893 | 2694 | 2821 | 2472 | 1962 | 1937 | 1597 | 1358 | 2069 | 1531 | 1472 | 1174 | 1715 | 1237 | |
Swell 2 Height (m) Direction Period (s) | SE 6 | — | SE 6 | — | — | SE 6 | SSE 6 | W 19 | SE 6 | SE 6 | S 26 | SE 6 | — | SSW 20 | SSW 18 | SW 21 | SW 20 | SW 18 | SE 4 | — | — |
21 | — | 38 | — | — | 38 | 27 | 7 | 37 | 60 | 13 | 32 | — | 790 | 835 | 72 | 186 | 522 | 16 | — | — | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | SE 7 | — | — | — | — | SSW 23 | — | — | — | — | — | — | — | — | — |
— | — | — | — | — | — | 85 | — | — | — | — | 54 | — | — | — | — | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | — | SE 6 | — | SE 7 | SE 6 | — | — | SE 6 | — | — | SE 5 | — | SE 5 | SE 4 | SE 5 | SE 4 | SE 4 | SE 5 | — | SE 4 | SE 5 |
— | 112 | — | 38 | 111 | — | — | 100 | — | — | 49 | — | 19 | 40 | 35 | 24 | 14 | 32 | — | 20 | 13 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 0 | 0 | 0 | 119 | 118 | 0 | 118 | 262 | 0 | 265 | 118 | 0 | 118 | 262 | 108 | 119 | 118 | 108 | 119 | 262 | 2 |
Best forecast wave conditions in Sumba | |||||||||||||||||||||
Best forecast wave conditions in Indonesia | |||||||||||||||||||||
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Information about the Wanjapu Surf forecast
The above surf forecast table for Wanjapu provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Wanjapu can be found by selecting the local surf guide option on the grey menu. Our Wanjapu 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 (Wanjapu) 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 Wanjapu 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.
Wanjapu is 24 km (15 miles) from the city of Adalara. If you plan a holiday in Sumba, look for hotels and other accommodation in Adalara. Adalara has rooms for a wide range of budgets as well as car hire and transport links.











