Surf Forecasts:
Nanwan Beach (South Bay) surf forecast from 16 Aug 2026:
- Best quality surf: Sunday 16 Aug, 11PM (local time) - 6ft (1.9m), 9s period, SW swell with cross-offshore winds.
- Most powerful swell: Saturday 22 Aug, 8AM (local time) - 10ft (3.0m), 10s period, SSW swell with 1,704 kJ wave energy.
- Next surfable swell (1★+): Sunday 16 Aug, 11PM (local time) - 6ft (1.9m), 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 1.9m and 9s period. 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 3.0m 10s and forecast to arrive on Saturday (Aug 22) at 8AM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 2.0m 6s period and expected on Tuesday (Aug 18) at 11PM.
| Wave Type | Time (CST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 11PM (Sun 16th Aug) | 6ft (1.9m) 9s |
| Best Surf | 11PM (Sun 16th Aug) | 6ft (1.9m) 9s |
| Most Powerful | 8AM (Sat 22nd Aug) | 10ft (3.0m) 10s |
Table - best surf conditions forecast for Nanwan Beach (South Bay) over the next 16 days.
The Lowdown
G'day, Rusty here. Let's have a look at what's cookin' for Nanwan Beach (South Bay) over the next couple of weeks. It's a bit of a mixed bag, so we gotta pick our moments. The water temp is bang on average for this time of year at 84°F, so no surprises there.
Right off the bat, the first surf worth paddling out for is Sunday afternoon, the 16th. We've got a 7ft SW swell rolling in, with a period of 8 seconds. The wind is a cross-offshore from the W at 12 mph, so it'll be clean enough. The combined energy is moderate, sitting at 694. It's not a standout, but it's something to get wet for.
Monday the 17th is a strange one. The morning is a write-off with a messy cross-shore, but Monday afternoon turns glassy with zero wind from the E. The swell drops to 5ft from the SW, but that glassy surface makes it a genuine option. It won't be big, but for a clean session, that's your best bet early on.
From Tuesday the 18th, things go quiet. We're looking at a string of days with poor conditions, strong winds, and messy surf. Honestly, from Tuesday morning right through to Sunday the 24th, it's mostly poor or marginal at best. There are a couple of calls on Friday the 21st afternoon and Saturday the 22nd where the swell picks back up to around 7ft to 7ft, but the wind is never quite right, leaving it lumpy or crossed up. It's a long, frustrating gap with no real green light.
Now, here's where it gets interesting. On Tuesday the 25th, we see a shift. The afternoon session has a tiny 2ft swell, but it's from the E with a very long period of 15 seconds. The wind is cross-off from the W, and the energy is moderate at 451. The comment says "expect good surf conditions." That long-period groundswell hitting a beach and reef setup can be tricky—it might break a bit straight—but if you can find a bank, those 15-second lines will have some push.
Thursday the 27th is the real standout in the second week. Morning and afternoon both show clean, cross-off winds from the W around 12 to 16 mph, with a 5ft to 5ft E swell. The period is a very long 14 seconds, and the energy jumps to a strong 1309 and 1192. That's serious power for the size. The swell direction from the E is a good match for the optimum SE direction, so it's lining up nicely. Just keep in mind that long-period E swell at a beach break can be a bit straight. It's probably best for the more experienced crew.
Friday the 28th holds similar clean conditions with a smaller 4ft to 4ft E swell and the same long period. It's a nice run, but not as powerful as Thursday.
The last few days of August get messy again. Saturday the 29th has a 8ft SSW swell, but the wind is a cross-shore from the ENE at 16 mph, making it rough. That's borderline too big for beginners anyway. Sunday and Monday stay average.
If you're looking for the best bang for your buck, circle Thursday the 27th. That's the one with the most power, cleanest wind, and a swell that's actually pointing in the right direction. The Tuesday 25th afternoon glass-off is a dark horse for a sneaky, clean session on that tiny E groundswell.
That's the story from here. Keep your eye on the horizon.
Rusty
Short Range ForecastLight rain (total 9mm), mostly falling on Sun night. Warm (max 30°C on Wed morning, min 27°C on Tue night). Winds increasing (calm on Mon morning, fresh winds from the NE by Tue night). | Days 5-7 Weather SummaryHeavy rain (total 64mm), heaviest during Thu night. Warm (max 29°C on Wed night, min 27°C on Thu night). Winds increasing (light winds from the SSW on Wed night, strong winds from the S by Thu morning). | ||||||||||||||||||
Monday 17 | Tuesday 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | ||||||||||||||
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 9 | SW 9 | SW 8 | SSW 8 | SW 8 | SW 8 | SW 9 | SW 9 | SW 9 | SSW 9 | SSW 10 | SSW 10 | SSW 10 | SSW 10 | SSW 10 | SSW 10 | SSW 10 | SSW 10 | SSW 10 |
Wave Graph | |||||||||||||||||||
481 | 390 | 311 | 235 | 154 | 162 | 182 | 152 | 107 | 288 | 356 | 527 | 1699 | 1184 | 1055 | 1593 | 1376 | 961 | 748 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | glassy | cross | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-on | on | cross-on | cross-on | cross-on | cross | cross | cross | cross-on | cross-on |
High Tide | 9:26PM0.83m | 9:33AM0.87m | 9:58PM0.88m | 10:10AM0.71m | 10:34PM0.92m | 10:51AM0.58m | 11:17PM0.93m | 12:03PM0.47m | 00:13AM0.94m | 1:28AM0.95m | 2:47AM0.98m | ||||||||
Low Tide | 3:20AM0.31m | 3:40PM0.33m | 4:21AM0.35m | 3:48PM0.38m | 5:35AM0.39m | 3:49PM0.42m | 7:25AM0.40m | 3:28PM0.44m | 9:52AM0.36m | 11:01AM0.29m | |||||||||
— | 5:35 | — | — | 5:35 | — | — | 5:35 | — | — | 5:35 | — | — | 5:35 | — | — | 5:35 | — | — | |
6:27 | — | 6:25 | — | — | 6:24 | — | — | 6:24 | — | — | 6:23 | — | — | 6:22 | — | — | 6:22 | — | |
mm | 5 | 3 | 1 | — | — | — | — | — | — | 6 | 5 | 5 | 18 | 9 | 8 | 8 | 4 | 1 | 19 |
Temp °C | 28 | 29 | 29 | 28 | 29 | 29 | 28 | 30 | 30 | 29 | 28 | 28 | 28 | 28 | 28 | 28 | 29 | 29 | 28 |
Feels °C | 32 | 34 | 33 | 30 | 30 | 28 | 27 | 32 | 34 | 34 | 27 | 28 | 28 | 28 | 28 | 31 | 31 | 31 | 31 |
Swell 1 Height (m) Direction Period (s) | SW 9 | SW 9 | SW 8 | SSW 8 | SW 8 | SW 8 | SW 9 | SW 9 | SW 9 | SSW 9 | SSW 10 | SSW 10 | SSW 10 | SE 10 | SSW 10 | ENE 8 | SSW 10 | SSW 10 | SSW 10 |
481 | 390 | 311 | 235 | 154 | 162 | 182 | 152 | 107 | 288 | 356 | 527 | 1699 | 108 | 1055 | 7 | 1376 | 961 | 748 | |
Swell 2 Height (m) Direction Period (s) | ENE 10 | ENE 10 | ENE 10 | ENE 10 | ESE 10 | ESE 10 | SE 10 | NE 10 | SSW 11 | ENE 9 | ENE 8 | ENE 9 | SE 10 | ENE 8 | SE 9 | ENE 9 | ESE 10 | SE 8 | SE 8 |
41 | 40 | 39 | 39 | 11 | 10 | 4 | 24 | 78 | 111 | 82 | 149 | 68 | 13 | 84 | 7 | 9 | 23 | 14 | |
Swell 3 Height (m) Direction Period (s) | ESE 11 | ESE 11 | ESE 11 | ESE 11 | SE 7 | SE 7 | SE 8 | SE 10 | ENE 9 | SSE 10 | SE 9 | SE 10 | ENE 9 | NE 8 | ENE 8 | — | NE 8 | ESE 10 | ESE 10 |
12 | 11 | 11 | 11 | 2 | 2 | 2 | 4 | 32 | 9 | 43 | 77 | 42 | 18 | 6 | — | 3 | 10 | 20 | |
Wind waves Height (m) Direction Period (s) | — | — | — | NE 4 | NE 5 | NE 6 | ENE 6 | ENE 6 | ENE 6 | — | — | — | — | SSW 10 | — | SSW 10 | — | — | — |
— | — | — | 31 | 106 | 159 | 235 | 103 | 56 | — | — | — | — | 1184 | — | 1593 | — | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 14 | 0 | 2 | 0 | 316 | 860 | 1160 | 329 | 0 | 0 | 14 | 148 | 42 | 316 | 348 | 14 | 348 | 14 | 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.











