
Surf Forecasts:
Nanwan Beach (South Bay) surf forecast from 6 Aug 2026:
- Best quality surf: Thursday 6 Aug, 8PM (local time) - 3ft (0.9m), 9s period, SSW swell with cross-offshore winds.
- Most powerful swell: Sunday 9 Aug, 11PM (local time) - 15ft (4.5m), 10s period, SW swell with 4,420 kJ wave energy.
- Next surfable swell (1★+): Thursday 6 Aug, 8PM (local time) - 3ft (0.9m), 9s period with SSW 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 Thursday (Aug 06) at 8PM. The primary swell is predicted to be 0.9m 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 4.5m 10s and forecast to arrive on Sunday (Aug 09) at 11PM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 2.5m 17s period and expected on Thursday (Aug 06) at 8PM.
| Wave Type | Time (CST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 8PM (Thu 6th Aug) | 3ft (0.9m) 9s |
| Best Surf | 8PM (Thu 6th Aug) | 3ft (0.9m) 9s |
| Most Powerful | 11PM (Sun 9th Aug) | 15ft (4.5m) 10s |
Table - best surf conditions forecast for Nanwan Beach (South Bay) over the next 16 days.
The Lowdown
Alright, let’s get into it. Rusty here, bringing you the word on the waves for the next couple of weeks.
First off, I gotta be straight with you – the start of this outlook is a rough one. We’ve got a long, frustrating gap with no real surf to recommend. From now until the morning of Thursday, August 21st, the conditions are just plain ugly. There’s a lot of swell, sure, but it’s all blown to hell by strong winds. We’re talking near-gale force cross-offshores whipping up those swells, making a mess of things. The swell itself gets properly big – up to 15 ft on the 9th – but with those winds, it’s a total write-off for a paddle. Honestly, for a beach and reef setup like Nanwan Beach (South Bay), that kind of power with that wind is more of a kite surfer’s dream than a surfer’s. The combined wave energy hits some massive numbers (3784 on the 9th), but it’s all for nothing.
For days and days, it’s just poor surf with cross-off and cross winds, and even when the swell drops a bit, the conditions are still marginal at best. The water temp is pretty much average for the time of year at 85°, so at least you won’t freeze while you’re watching the chaos.
But hang in there, because the end of the tunnel is where the real deal shows up. Finally, on Friday, August 21st, things turn around. The wind drops right out, going light and cross-offshore from the WNW. The swell from the SSW starts to build proper, with a nice long period that hits 12 seconds – that’s a proper groundswell, full of energy. We’re talking 8 ft of clean, lined-up swell. The combined energy jumps to 1697, which is solid, and the forecast says it’s excellent for experienced surfers. This is the standout, no question. A long-period SSW swell like that, with glassy cross-offshore winds, will make Nanwan Beach (South Bay) an absolute gem. The sets will be clean, the waves will have shape, and the gaps between them will make paddling out a breeze. It’s the kind of session you wait for. Just keep in mind, with that kind of quality, the crowds are often an issue, so get in early.
The week before that, leading into the 21st, you’ll start to see the swell settle and the winds back off, but it’s still not worth getting too excited about. A few days in the second week show some marginal calls with clean surf, but the swell sizes are smaller and the energy is weaker. It’s a slow build to that Friday payoff.
So, the bottom line: the first three weeks are a write-off. Don’t even bother. But if you can hold out, Friday, August 21st is the golden ticket. The wind, the swell, the period – it all lines up. That’s your day.
Rusty.
Short Range ForecastLight rain (total 6mm), mostly falling on Sat afternoon. Warm (max 30°C on Sat night, min 28°C on Thu night). Winds increasing (light winds from the WNW on Thu afternoon, near gales from the W by Sat night). | Days 5-7 Weather SummaryHeavy rain (total 37mm), heaviest during Sun night. Warm (max 30°C on Sun afternoon, min 28°C on Tue night). Winds decreasing (near gales from the WSW on Sun night, fresh winds from the WSW by Tue afternoon). | |||||||||||||||||||
Thu 6 | Friday 7 | Saturday 8 | Sunday 9 | Monday 10 | Tuesday 11 | Wednesday 12 | ||||||||||||||
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) | SSW 9 | SW 8 | SSW 7 | SW 8 | WSW 6 | WSW 7 | WSW 8 | SW 9 | SW 9 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 |
Wave Graph | ||||||||||||||||||||
151 | 96 | 48 | 59 | 350 | 853 | 1067 | 2033 | 3174 | 3782 | 4372 | 3314 | 2406 | 2152 | 1516 | 1297 | 1162 | 940 | 886 | 761 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross | cross-off | cross | cross | cross | cross | cross | cross-off | cross-off | cross-off |
High Tide | 00:31AM0.99m | 2:26PM0.49m | 1:43AM1.07m | 5:31PM0.49m | 2:58AM1.15m | 6:13PM0.51m | 4:05AM1.24m | 6:39PM0.52m | 5:05AM1.31m | 7:05PM0.54m | 5:59AM1.35m | 7:32PM0.57m | ||||||||
Low Tide | 5:03PM0.41m | 8:36AM0.31m | 5:28PM0.46m | 10:14AM0.20m | 6:01PM0.49m | 11:21AM0.09m | 8:02PM0.49m | 12:12PM0.02m | 9:36PM0.46m | 12:56PM-0.02m | 10:47PM0.40m | 1:35PM-0.01m | 11:46PM0.34m | |||||||
— | — | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — | 5:33 | — | — | 5:33 | — | — | |
6:34 | — | — | 6:32 | — | — | 6:32 | — | — | 6:31 | — | — | 6:30 | — | — | 6:30 | — | — | 6:30 | — | |
mm | — | — | — | — | — | — | 1 | 3 | 2 | 2 | 5 | 6 | 4 | 8 | 2 | 2 | 5 | 3 | 1 | 2 |
Temp °C | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 30 | 30 | 30 | 30 | 30 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 |
Feels °C | 32 | 33 | 29 | 27 | 28 | 27 | 26 | 28 | 26 | 27 | 27 | 27 | 27 | 28 | 30 | 29 | 30 | 30 | 29 | 30 |
Swell 1 Height (m) Direction Period (s) | ENE 17 | ENE 16 | ENE 16 | ENE 16 | ENE 15 | NE 14 | NE 15 | NNE 14 | NNE 14 | NNE 13 | ENE 15 | ENE 15 | ENE 15 | ENE 14 | ENE 13 | ENE 13 | ENE 12 | SW 10 | SW 10 | ENE 11 |
3712 | 3178 | 2895 | 2417 | 1297 | 891 | 844 | 357 | 115 | 16 | 21 | 44 | 72 | 152 | 137 | 135 | 119 | 940 | 886 | 71 | |
Swell 2 Height (m) Direction Period (s) | SSW 9 | — | SSW 7 | SW 8 | — | — | ENE 12 | E 11 | SE 10 | ENE 15 | ENE 15 | SE 11 | SE 10 | SE 10 | SE 10 | SE 9 | SE 9 | ENE 12 | ENE 12 | SE 8 |
151 | — | 48 | 59 | — | — | 14 | 10 | 4 | 21 | 42 | 29 | 26 | 25 | 47 | 43 | 40 | 83 | 79 | 17 | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | SE 10 | SE 10 | E 11 | E 11 | NNE 12 | — | — | — | — | — | — | SE 9 | SE 8 | — |
— | — | — | — | — | — | 4 | 4 | 2 | 2 | 13 | — | — | — | — | — | — | 19 | 18 | — | |
Wind waves Height (m) Direction Period (s) | — | SW 8 | WNW 5 | WNW 6 | WSW 6 | WSW 7 | WSW 8 | SW 9 | SW 9 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | — | — | SW 10 |
— | 96 | 75 | 155 | 350 | 853 | 1067 | 2033 | 3174 | 3782 | 4372 | 3314 | 2406 | 2152 | 1516 | 1297 | 1162 | — | — | 761 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 2 | 148 | 676 | 42 | 148 | 538 | 316 | 148 | 316 | 316 | 316 | 148 | 329 | 148 | 375 | 348 | 148 | 363 | 42 | 329 |
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.











