
Surf Forecasts:
Nanwan Beach (South Bay) surf forecast from 9 Aug 2026:
- Best quality surf: Sunday 16 Aug, 11PM (local time) - 7.5ft (2.3m), 9s period, SW swell with cross-offshore winds.
- Most powerful swell: Monday 10 Aug, 11AM (local time) - 11ft (3.5m), 9s period, SW swell with 1,967 kJ wave energy.
- Next surfable swell (1★+): Sunday 16 Aug, 11PM (local time) - 7.5ft (2.3m), 9s period with SW swell.
Best Forecast Surf Conditions for Nanwan Beach (South Bay) this week:
The surf forecast for Nanwan Beach (South Bay) over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Sunday (Aug 16) at 11PM. The primary swell is predicted to be 2.3m and 9s period with a secondary swell of 0.2m and 11s. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Nanwan Beach (South Bay) in the next 16 days are 3.5m 9s and forecast to arrive on Monday (Aug 10) at 11AM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.7m 14s period and expected on Tuesday (Aug 11) at 2AM.
| Wave Type | Time (CST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 11PM (Sun 16th Aug) | 7.5ft (2.3m) 9s |
| Best Surf | 11PM (Sun 16th Aug) | 7.5ft (2.3m) 9s |
| Most Powerful | 11AM (Mon 10th Aug) | 11ft (3.5m) 9s |
Table - best surf conditions forecast for Nanwan Beach (South Bay) over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s talk about what’s cooking for Nanwan Beach (South Bay) over the next couple of weeks.
Right off the bat, it’s a rough start. The first few days are a write-off with a big, stormy SW swell that’s got a lot of energy (1992) but it’s being trashed by strong cross-shore winds. It’s messy, it’s ugly, and the risk of thunderstorms is a constant buzzkill. For the first week, honestly, you’re better off doing something else. The wind stays stubborn from the west, keeping things cross-off and mostly clean, but the swell is just too wind-affected and the quality is poor. It’s a real grind.
We start to see a glimmer of hope around Wednesday the 12th of August, with the swell dropping to a more manageable 7ft to 7ft from the SW. The wind lightens up a bit, and the surface cleans up. It’s still a marginal call, but the bumps are gone. That trend holds through the weekend, with the swell staying in the 7ft to 8ft range and the wind keeping a clean cross-off angle. The energy is moderate (around 700-900), but the consistency is just okay.
Now, here’s the standout for the whole run. Monday the 17th of August is the day to circle. The morning sees a lighter WSW wind, dropping to a gentle breeze, and the waves are a solid 8ft from the SSW with moderate energy (875). The water temp is about average for the time of year. Then the afternoon gets even better: the wind swings to a light offshore from the NNW at just 3 mph, the sky clears, and the swell is 6ft from the SW. It’s going to be clean, lined up, and way more fun than anything else in the period. The combo of light offshore and a solid SW groundswell is a rare treat here.
The next morning, Tuesday the 18th of August, also looks excellent. The wind goes glassy, calm, and the swell is still a nice 6ft from the SSW. It’s a bit smaller, but the glassy conditions will make it silky smooth. That’s your second-best window.
After that, it’s a slow fade. The wind picks up from the NE again, and the swell drops below 5ft, making it mostly a write-off. By the end of the month, the wind goes onshore from the south, and the swell is on the rise again. Tuesday the 25th of August, the swell is predicted to be a massive 13ft from the SSW with a very long period of 11 seconds and a massive energy reading of 7739. That is way too big for this beach-and-reef setup, and with a cross-shore wind, it’s only for the most experienced, and even then, it’s a dangerous beast. The crowd profile says “often” busy, so expect a full parking lot if you’re brave enough.
So, for the best surf, hit the water on Monday the 17th of August afternoon or Tuesday morning the 18th of August. The rest is a waiting game.
Rusty.
Short Range ForecastHeavy rain (total 43mm), heaviest during Mon morning. Warm (max 29°C on Sun night, min 28°C on Mon night). Mainly strong winds. | Days 5-7 Weather SummaryHeavy rain (total 28mm), heaviest during Sat morning. Warm (max 29°C on Wed night, min 28°C on Wed night). Mainly fresh winds. | ||||||||||||||||||
Monday 10 | Tuesday 11 | Wednesday 12 | Thursday 13 | Friday 14 | Saturday 15 | ||||||||||||||
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 10 | SW 9 | SW 9 | SW 9 | SW 9 | SW 9 | SW 10 | SW 9 | SW 9 | SW 10 | SW 9 | SSW 9 | SW 9 | SSW 9 | SSW 9 | SW 9 | SW 9 | SW 9 | SW 9 |
Wave Graph | |||||||||||||||||||
1819 | 1967 | 1681 | 1283 | 968 | 899 | 766 | 703 | 678 | 653 | 537 | 541 | 586 | 676 | 637 | 649 | 890 | 753 | 727 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross | cross | cross | cross | cross | cross | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross |
High Tide | 4:05AM1.24m | 6:39PM0.52m | 5:05AM1.31m | 7:05PM0.54m | 5:59AM1.35m | 7:32PM0.57m | 6:48AM1.35m | 7:59PM0.62m | 7:33AM1.28m | 8:26PM0.69m | 8:15AM1.17m | 8:55PM0.76m | |||||||
Low Tide | 8:02PM0.49m | 12:12PM0.02m | 9:36PM0.46m | 12:56PM-0.02m | 10:47PM0.40m | 1:35PM-0.01m | 11:46PM0.34m | 2:10PM0.03m | 00:41AM0.30m | 2:39PM0.10m | 1:33AM0.28m | 3:05PM0.18m | 2:26AM0.28m | ||||||
— | 5:31 | — | — | 5:33 | — | — | 5:33 | — | — | 5:33 | — | — | 5:33 | — | — | 5:33 | — | — | |
6:31 | — | 6:30 | — | — | 6:30 | — | — | 6:30 | — | — | 6:29 | — | — | 6:28 | — | — | 6:28 | — | |
mm | 7 | 5 | 4 | 9 | 4 | 3 | 7 | 3 | 1 | 2 | 2 | 2 | 4 | 1 | 1 | 6 | 5 | 5 | 19 |
Temp °C | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 28 |
Feels °C | 29 | 28 | 29 | 30 | 31 | 30 | 32 | 30 | 30 | 32 | 30 | 30 | 31 | 30 | 30 | 31 | 30 | 30 | 31 |
Swell 1 Height (m) Direction Period (s) | SE 10 | ENE 15 | ENE 15 | ENE 14 | ENE 13 | SW 9 | ENE 12 | SW 9 | SW 9 | SW 10 | SW 9 | SSW 9 | ENE 10 | SSW 9 | SSW 9 | ENE 10 | SW 9 | ENE 10 | ENE 11 |
16 | 73 | 123 | 201 | 181 | 899 | 117 | 703 | 678 | 653 | 537 | 541 | 41 | 676 | 637 | 20 | 766 | 10 | 11 | |
Swell 2 Height (m) Direction Period (s) | ENE 15 | SE 10 | SE 10 | SE 10 | SE 10 | ENE 13 | SE 9 | ENE 12 | ENE 12 | ENE 12 | ENE 11 | ENE 11 | SE 8 | NE 10 | NE 10 | SSE 8 | ENE 10 | SSE 8 | SSE 8 |
21 | 25 | 24 | 24 | 47 | 178 | 36 | 113 | 78 | 78 | 47 | 46 | 16 | 26 | 26 | 6 | 10 | 7 | 6 | |
Swell 3 Height (m) Direction Period (s) | ENE 11 | NNE 10 | NE 11 | NE 11 | N 8 | SE 9 | — | SSE 8 | SE 8 | SE 8 | SE 9 | SE 8 | N 8 | N 8 | SSE 8 | SE 11 | SE 11 | SE 11 | ESE 10 |
11 | 10 | 5 | 5 | 1 | 41 | — | 28 | 35 | 16 | 19 | 18 | 1 | 1 | 7 | 5 | 5 | 5 | 10 | |
Wind waves Height (m) Direction Period (s) | SW 10 | SW 9 | SW 9 | SW 9 | SW 9 | — | SW 10 | — | — | — | — | — | SW 9 | — | — | SW 9 | SW 9 | SW 9 | SW 9 |
1819 | 1967 | 1681 | 1283 | 968 | — | 766 | — | — | — | — | — | 586 | — | — | 649 | 890 | 753 | 727 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 316 | 148 | 148 | 148 | 378 | 329 | 148 | 42 | 42 | 316 | 363 | 42 | 329 | 348 | 42 | 348 | 639 | 42 | 14 |
Best forecast wave conditions in South Taiwan | |||||||||||||||||||
Best forecast wave conditions in Taiwan | |||||||||||||||||||
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Information about the Nanwan Beach (South Bay) Surf forecast
The above surf forecast table for Nanwan Beach (South Bay) provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Nanwan Beach (South Bay) can be found by selecting the local surf guide option on the grey menu. Our Nanwan Beach (South Bay) 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 (Nanwan Beach (South Bay)) 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 Nanwan Beach (South Bay) 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.











