
Surf Forecasts:
Nanwan Beach (South Bay) surf forecast from 5 Aug 2026:
- Best quality surf: Sunday 9 Aug, 8AM (local time) - 13ft (4.0m), 9s period, WSW swell with cross-offshore winds.
- Most powerful swell: Monday 10 Aug, 5AM (local time) - 13ft (4.0m), 10s period, SW swell with 3,105 kJ wave energy.
- Next surfable swell (1★+): Wednesday 5 Aug, 8PM (local time) - 2.5ft (0.8m), 8s 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 Wednesday (Aug 05) at 8PM. The primary swell is predicted to be 0.8m and 8s period. The wind is predicted to be offshore as the swell arrives.
The most powerful waves expected at Nanwan Beach (South Bay) in the next 16 days are 4.0m 10s and forecast to arrive on Monday (Aug 10) at 5AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 3.0m 17s period and expected on Friday (Aug 07) at 2PM.
| Wave Type | Time (CST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 8PM (Wed 5th Aug) | 2.5ft (0.8m) 8s |
| Best Surf | 8AM (Sun 9th Aug) | 13ft (4.0m) 9s |
| Most Powerful | 5AM (Mon 10th Aug) | 13ft (4.0m) 10s |
Table - best surf conditions forecast for Nanwan Beach (South Bay) over the next 16 days.
The Lowdown
Alright, this is Rusty, checking in from the South Bay. Right now, we’re looking at a bit of a slow start, but there’s some serious potential down the line, if you’re willing to wait for it.
The first real surf on offer kicks off on Wednesday afternoon, August 5th, at Nanwan Beach (South Bay). We’ve got a solid chest-to-head high groundswell rolling in from the East at 6ft, with a super long period of 17 seconds. That long period means the energy is deep and powerful, and with a combined energy of 2082 (moderate), it’s got some grunt. The water temp is sitting right around 86°F, which is pretty average for this time of year. The wind is a gentle offshore from the NW, keeping things clean. This is an excellent session for experienced surfers, but be aware, the long period makes it tricky at a beach-and-reef setup – it’ll be lining up better on the reef sections. Also, this spot can get crowded often, so get there early.
Things drop off after that. Thursday, August 6th, fades to small, weak waves around 4ft with a short period, and the wind goes cross-offshore. The energy drops to 208 (weak), and it’s pretty ordinary. Friday and Saturday are a write-off with howling winds in the 25-31 mph range, making a mess of things. Sunday, August 9th, through Tuesday, August 11th, sees a massive, dangerous swell hit – 12ft to 13ft from the SW. The combined energy peaks at 2980 (strong) on Sunday. This is way too big for this break, and even the wind reports say it’s favorable but the swell is too big. Forget about it unless you’re a madman. The whole first week is a slog.
The second week finally shows some life. From Friday, August 14th, the swell settles back to a more manageable 7ft from the SW, with a period of 9 seconds. The energy is 689 (weak to moderate). The wind is light, so things will be clean. It’s a marginal forecast, but the conditions are looking good for a solid session. The best bet of the whole run actually looks like Wednesday, August 19th. We get a 6ft SW swell with a 10-second period, combined energy of 728 (moderate), and a light offshore from the NW in the morning. The forecast says "very good surf conditions." That’s your standout window. It’s not a monster, but it’s clean, rideable, and the most promising day in a pretty rough forecast.
Overall, there’s a huge gap of poor to dangerous surf from the 6th through the 13th. Patience is key. The highlight is the 19th, but the 5th is a quality, powerful session for the crew that can handle it.
Stay frothy,
Rusty
Short Range ForecastMostly dry. Warm (max 30°C on Sat morning, min 28°C on Wed night). Winds increasing (light winds from the WSW on Thu afternoon, strong winds from the WNW by Fri night). | Days 5-7 Weather SummaryLight rain (total 7mm), mostly falling on Mon afternoon. Warm (max 31°C on Sun morning, min 29°C on Sat afternoon). Mainly strong winds. | |||||||||||||||||||
Wed 5 | Thursday 6 | Friday 7 | Saturday 8 | Sunday 9 | Monday 10 | Tuesday 11 | ||||||||||||||
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) | E 17 | SSW 9 | SSW 9 | SSW 8 | SW 8 | SW 8 | SW 9 | WSW 6 | WSW 8 | WSW 8 | SW 9 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 |
Wave Graph | ||||||||||||||||||||
2023 | 308 | 208 | 113 | 86 | 57 | 112 | 440 | 998 | 1118 | 1989 | 2952 | 2817 | 2720 | 2422 | 2229 | 2067 | 2026 | 2008 | 1500 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | off | cross-off | cross-off | cross-off | cross-off | cross-off | 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 |
High Tide | 11:31PM0.93m | 12:04PM0.58m | 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 | ||||||||
Low Tide | 4:40PM0.37m | 6:37AM0.37m | 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 | |||||||
— | — | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — | 5:31 | — | — | 5:33 | — | — | |
6:34 | — | — | 6:34 | — | — | 6:32 | — | — | 6:32 | — | — | 6:31 | — | — | 6:30 | — | — | 6:30 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 3 | 2 | 2 | 3 | 5 |
Temp °C | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 30 | 30 | 30 | 31 | 31 | 30 | 30 | 30 | 30 | 30 | 30 | 29 |
Feels °C | 32 | 33 | 33 | 34 | 33 | 28 | 27 | 28 | 28 | 28 | 28 | 30 | 30 | 28 | 29 | 28 | 27 | 27 | 27 | 27 |
Swell 1 Height (m) Direction Period (s) | E 17 | ENE 18 | ENE 18 | ENE 17 | ENE 17 | ENE 17 | ENE 17 | ENE 16 | NE 16 | NE 16 | NE 15 | NNE 15 | NE 15 | NNE 15 | NNE 14 | ENE 15 | ENE 14 | ENE 14 | ENE 13 | ENE 13 |
2023 | 2552 | 3753 | 3712 | 3767 | 4043 | 4606 | 2032 | 1739 | 1664 | 1019 | 780 | 503 | 279 | 81 | 71 | 110 | 113 | 101 | 96 | |
Swell 2 Height (m) Direction Period (s) | S 9 | SSW 9 | SSW 9 | SSW 8 | — | SW 8 | SW 9 | — | — | — | SE 10 | SSE 11 | SE 10 | SE 10 | SE 10 | SE 10 | SE 10 | SE 10 | SE 10 | SE 10 |
39 | 308 | 208 | 113 | — | 57 | 112 | — | — | — | 4 | 11 | 17 | 17 | 28 | 27 | 26 | 25 | 23 | 23 | |
Swell 3 Height (m) Direction Period (s) | SE 9 | — | — | — | — | — | — | — | — | — | — | E 15 | E 15 | E 15 | ENE 15 | NNE 13 | NNE 12 | N 11 | — | — |
13 | — | — | — | — | — | — | — | — | — | — | 17 | 17 | 17 | 42 | 18 | 13 | 2 | — | — | |
Wind waves Height (m) Direction Period (s) | W 6 | — | — | — | SW 8 | WNW 5 | WNW 6 | WSW 6 | WSW 8 | WSW 8 | SW 9 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SW 10 |
7 | — | — | — | 86 | 95 | 194 | 440 | 998 | 1118 | 1989 | 2952 | 2817 | 2720 | 2422 | 2229 | 2067 | 2026 | 2008 | 1500 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 0 | 0 | 0 | 0 | 148 | 676 | 79 | 148 | 538 | 148 | 148 | 390 | 42 | 148 | 316 | 316 | 148 | 148 | 148 | 148 |
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.











