Surf Forecasts:
Nanwan Beach (South Bay) surf forecast from 20 Aug 2026:
- Best quality surf: Monday 24 Aug, 11PM (local time) - 8ft (2.5m), 10s period, SSW swell with cross-offshore winds.
- Most powerful swell: Tuesday 25 Aug, 2PM (local time) - 6ft (1.8m), 17s period, E swell with 1,881 kJ wave energy.
- Next surfable swell (1★+): Monday 24 Aug, 11PM (local time) - 8ft (2.5m), 10s 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 Monday (Aug 24) at 11PM. The primary swell is predicted to be 2.5m and 10s period with a secondary swell of 1.2m and 18s. 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 1.8m 17s and forecast to arrive on Tuesday (Aug 25) at 2PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.6m 16s period and expected on Tuesday (Aug 25) at 11PM.
| Wave Type | Time (CST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 11PM (Mon 24th Aug) | 8ft (2.5m) 10s |
| Best Surf | 11PM (Mon 24th Aug) | 8ft (2.5m) 10s |
| Most Powerful | 2PM (Tue 25th Aug) | 6ft (1.8m) 17s |
Table - best surf conditions forecast for Nanwan Beach (South Bay) over the next 16 days.
The Lowdown
Alright folks, Rusty here, looking at the next couple of weeks for us. It's a bit of a mixed bag, so let’s get into it.
First up, the water is sitting at a pretty typical 84°F for this time of year, so no surprises there.
The next few days are looking pretty average. From Thursday the 20th through to Monday the 24th, we've got a moderate to fresh cross-shore wind blowing, with a modest 8ft to 10ft SSW swell. The energy is moderate, but the wind is making things messy. Combine that with rain and a risk of thunderstorms, and it's not the best time to be out. The surf will be lumpy, and conditions are just marginal. There's a bit of a clean-up on the Friday afternoon, but the wind is still fresh.
The first real standout shows up on Tuesday the 25th. The morning sees a shift, and by the afternoon, it's looking really good at Nanwan Beach (South Bay). We have a 6ft swell from the east, but here's the kicker – it's a long-period groundswell at 16 seconds, which brings a ton of energy. The wind swings light and offshore from the northwest, giving us clean, glassy conditions. This is a great option for experienced surfers, but that long period can make the sets a bit more spaced out. The crowd factor is "often", so expect company.
Wednesday the 26th afternoon also looks promising. The swell drops a touch to 6ft from the SW, but the wind goes glassy from the west. The energy is moderate, but the clean conditions will make for some very good surf. Again, expect some crowds.
From Thursday the 27th onwards, the quality drops off again. The wind goes onshore or cross-shore, and the swell energy weakens. We get a bit of a lull for a few days, with just poor surf conditions.
Then, things get interesting again. On Monday the 31st of August, we see a massive pulse of 13ft swell from the SSW. The energy is pumping, and conditions are wind and tide favorable. However, that is serious size – 13ft is only for the experts. The same goes for Tuesday the 1st of September, with a 13ft SSW swell and light cross-onshore wind. This is a proper big-wave session, but it's over a week away, so keep an eye on it.
The energy drops back down after that, with 10ft swell on the 2nd and 8ft on the 3rd, but the wind stays tricky. The period shortens, and the conditions become marginal again. The final few days drop off to a poor 4ft to 4ft from the SW with a strong, clean offshore wind, but there's just not enough swell to get excited about.
So, the best bets are the Tuesday afternoon, August 25th, and the Wednesday afternoon, August 26th. The big swell at the end of the month is a watch-and-see for the experts.
Rusty.
Short Range ForecastHeavy rain (total 144mm), heaviest during Fri afternoon. Warm (max 28°C on Thu morning, min 26°C on Thu night). Mainly fresh winds. | Days 4-6 Weather SummaryHeavy rain (total 124mm), heaviest during Tue morning. Warm (max 28°C on Sun morning, min 26°C on Tue morning). Winds decreasing (fresh winds from the WSW on Sun morning, calm by Tue night). | ||||||||||||||||||||
Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | Tuesday 25 | Wednesday 26 | |||||||||||||||
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) | SSW 9 | SW 9 | SSW 9 | SW 10 | SW 10 | SW 10 | SW 10 | SW 9 | SW 9 | SW 9 | SW 9 | SW 9 | SW 9 | SSW 10 | SW 10 | E 18 | E 16 | SW 10 | SSW 10 | SW 10 | SW 10 |
Wave Graph | |||||||||||||||||||||
1060 | 1104 | 1388 | 1764 | 1631 | 1290 | 1013 | 1132 | 1247 | 1010 | 1209 | 1102 | 844 | 1149 | 1456 | 1759 | 1730 | 799 | 855 | 725 | 832 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross-off | cross | cross-off | cross-off | cross-off | cross-off | cross-off | cross | cross-off | cross | cross-off | cross | cross | cross | cross-off | cross-off | glassy | on | glassy | glassy |
High Tide | 12:03PM0.47m | 00:13AM0.94m | 1:28AM0.95m | 2:47AM0.98m | 3:51AM1.03m | 6:41PM0.54m | 4:42AM1.09m | 6:38PM0.56m | 5:24AM1.14m | 6:49PM0.59m | |||||||||||
Low Tide | 3:28PM0.44m | 9:52AM0.36m | 11:01AM0.29m | 11:37AM0.24m | 12:05PM0.19m | 9:07PM0.52m | 12:31PM0.16m | 10:17PM0.46m | 12:55PM0.14m | 11:07PM0.40m | |||||||||||
5:35 | — | — | 5:35 | — | — | 5:35 | — | — | 5:37 | — | — | 5:37 | — | — | 5:37 | — | — | 5:37 | — | — | |
— | 6:23 | — | — | 6:22 | — | — | 6:22 | — | — | 6:21 | — | — | 6:21 | — | — | 6:20 | — | — | 6:19 | — | |
mm | 11 | 11 | 26 | 17 | 34 | 17 | 6 | 5 | 17 | 11 | 7 | 20 | 8 | 6 | 21 | 24 | 12 | 15 | 34 | 9 | — |
Temp °C | 28 | 27 | 28 | 27 | 27 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 27 | 26 | 27 | 25 | 26 | 27 |
Feels °C | 29 | 29 | 28 | 27 | 29 | 29 | 28 | 27 | 28 | 28 | 28 | 30 | 31 | 30 | 31 | 30 | 29 | 32 | 29 | 31 | 32 |
Swell 1 Height (m) Direction Period (s) | ENE 8 | SW 9 | ENE 8 | ENE 8 | SW 10 | SW 10 | ESE 10 | ESE 10 | ESE 10 | E 10 | NE 13 | SW 9 | SW 9 | SSW 10 | SW 10 | SW 10 | SW 10 | SW 10 | SSW 10 | SW 10 | SW 10 |
38 | 1104 | 27 | 13 | 1631 | 1290 | 10 | 10 | 10 | 17 | 42 | 1102 | 844 | 1149 | 1200 | 1037 | 999 | 799 | 855 | 725 | 832 | |
Swell 2 Height (m) Direction Period (s) | SE 10 | ENE 8 | SE 8 | — | ENE 8 | ENE 8 | ENE 8 | ENE 8 | ENE 9 | E 16 | E 17 | ESE 16 | ENE 11 | ENE 9 | E 18 | E 18 | E 16 | E 15 | ENE 15 | ENE 14 | ENE 14 |
14 | 26 | 18 | — | 7 | 7 | 7 | 7 | 7 | 5 | 23 | 87 | 166 | 145 | 1177 | 1759 | 1730 | 1060 | 886 | 668 | 522 | |
Swell 3 Height (m) Direction Period (s) | — | SE 9 | — | — | ENE 8 | ESE 10 | — | E 14 | — | E 16 | ESE 10 | NE 10 | E 15 | E 19 | NE 9 | NE 10 | NE 9 | NE 10 | SE 12 | ENE 8 | ENE 8 |
— | 21 | — | — | 7 | 10 | — | 4 | — | 5 | 10 | 23 | 110 | 343 | 152 | 170 | 216 | 260 | 5 | 111 | 37 | |
Wind waves Height (m) Direction Period (s) | SSW 9 | — | SSW 9 | SW 10 | — | — | SW 10 | SW 9 | SW 9 | SW 9 | SW 9 | — | — | — | SW 10 | — | — | — | NE 10 | — | — |
1060 | — | 1388 | 1764 | — | — | 1013 | 1132 | 1247 | 1010 | 1209 | — | — | — | 1456 | — | — | — | 207 | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 348 | 14 | 42 | 42 | 348 | 316 | 42 | 148 | 316 | 348 | 42 | 14 | 14 | 42 | 14 | 14 | 0 | 0 | 14 | 0 | 0 |
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.











