Surf Forecasts:
Nanwan Beach (South Bay) surf forecast from 25 Aug 2026:
- Best quality surf: Saturday 29 Aug, 2AM (local time) - 6ft (1.8m), 9s period, SW swell with cross-offshore winds.
- Most powerful swell: Tuesday 25 Aug, 5PM (local time) - 8ft (2.4m), 17s period, E swell with 3,355 kJ wave energy.
- Next surfable swell (1★+): Tuesday 25 Aug, 8PM (local time) - 6.5ft (2.0m), 8s 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 Tuesday (Aug 25) at 8PM. The primary swell is predicted to be 2.0m and 8s 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 2.4m 17s and forecast to arrive on Tuesday (Aug 25) at 5PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 2.4m 17s period and expected on Tuesday (Aug 25) at 8PM.
| Wave Type | Time (CST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 8PM (Tue 25th Aug) | 6.5ft (2.0m) 8s |
| Best Surf | 2AM (Sat 29th Aug) | 6ft (1.8m) 9s |
| Most Powerful | 5PM (Tue 25th Aug) | 8ft (2.4m) 17s |
Table - best surf conditions forecast for Nanwan Beach (South Bay) over the next 16 days.
The Lowdown
Alright, this is Rusty comin' at ya from the South Bay.
Well, it’s a bit of a mixed bag lookin’ ahead at Nanwan Beach. We’ve got some decent swell energy on the horizon, but the timing and winds are gonna be the real deal-breakers for the next week or so. Water temps are sittin’ right around 84°, which is pretty much bang-on average for this time of year, so you won't need a thick suit, just a good rashie.
The first real glimmer of something worthwhile ain't until later on. We’ll be sittin' through a stretch of marginal to poor conditions from the 25th through into early September. There’s size, but the wind patterns are messy—gusty westerlies and onshores kickin’ up a chop and bringin’ a risk of storms. It’s not your call to be in the water then. The swell energy through this period is moderate, but the quality just isn’t there.
Now, things start to turn around on Thursday, the 3rd of September. The morning is lookin’ magic—dead glassy conditions with a light 6ft groundswell from the southwest and a period of 9 seconds. That glassy surface will have the waves lookin’ clean as a whistle. Thursday afternoon gets even better, with more energy and glassy conditions. This is a good session for the intermediate crew, no doubt.
But the true standout of the whole run is Friday, the 4th of September. This is the one. We get a solid pulse of 10ft swell from the southwest, with a period stretching to 12 seconds—that’s proper groundswell energy. The combined energy jumps up, and the winds are light and offshore out of the west. The waves will have some real punch and shape to ’em. Keep in mind though, this is only for experienced surfers; at 10ft, it’s gonna be beyond what beginners want to paddle into, especially with those long-period sets. The break is a beach and reef setup, and that long-period swell can sometimes make things a bit straight at beach breaks, but the offshore wind should help hold it together nicely. Expect crowds to be around—this spot gets busy when it’s good.
After that, the swell jumps up to a massive 18ft on the 5th and 6th, but frankly, that’s just too big for Nanwan Beach. The energy is insane, but it’s a danger zone, not a fun zone. That’s one for the big-wave chargers only, if they dare.
We wind down the outlook with the 7th into the 8th of September, where the size drops back to the 8ft to 5ft range. The 7th Monday morning looks really nice: 8ft of west swell with glassy conditions and a period of 10 seconds. That’s excellent for strong intermediates. By the 9th, it’s fadin’ out to small, ordinary waves.
So, to call it: Friday the 4th is your best bet by a long shot—big, clean, and powerful.
Rusty.
Short Range ForecastHeavy rain (total 43mm), heaviest during Tue morning. Warm (max 28°C on Tue night, min 27°C on Tue morning). Winds increasing (light winds from the W on Tue night, strong winds from the W by Thu night). | Days 4-6 Weather SummaryModerate rain (total 11mm), heaviest on Fri night. Warm (max 29°C on Fri afternoon, min 27°C on Sun night). Winds increasing (light winds from the WSW on Fri night, strong winds from the ENE by Sun afternoon). | ||||||||||||||||||||
Tuesday 25 | Wednesday 26 | Thursday 27 | Friday 28 | Saturday 29 | Sunday 30 | Monday 31 | |||||||||||||||
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) | E 18 | E 17 | SW 9 | SW 9 | SW 9 | SW 9 | SW 9 | SW 8 | SW 8 | SW 8 | SW 8 | SW 9 | SSW 9 | SW 9 | SW 10 | SSW 10 | SSW 10 | SSW 10 | SSW 9 | SSW 9 | SSW 9 |
Wave Graph | |||||||||||||||||||||
2703 | 3355 | 594 | 571 | 760 | 585 | 668 | 760 | 702 | 746 | 781 | 528 | 1012 | 899 | 846 | 756 | 833 | 943 | 859 | 865 | 878 | |
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-off | cross-off | cross-off | cross-off | cross | cross-on | cross-off | cross-off | cross | cross-off | cross-off | cross-off | cross-off |
High Tide | 6:38PM0.56m | 5:24AM1.14m | 6:49PM0.59m | 6:02AM1.17m | 7:06PM0.64m | 6:38AM1.18m | 7:26PM0.70m | 7:13AM1.14m | 7:49PM0.76m | 7:48AM1.08m | 8:14PM0.84m | 8:25AM0.98m | 8:42PM0.91m | ||||||||
Low Tide | 12:31PM0.16m | 10:17PM0.46m | 12:55PM0.14m | 11:07PM0.40m | 1:18PM0.14m | 11:51PM0.35m | 1:39PM0.15m | 00:35AM0.30m | 2:00PM0.18m | 1:18AM0.26m | 2:19PM0.22m | 2:05AM0.24m | 2:38PM0.27m | 2:55AM0.24m | |||||||
5:37 | — | — | 5:37 | — | — | 5:37 | — | — | 5:37 | — | — | 5:39 | — | — | 5:39 | — | — | 5:39 | — | — | |
— | 6:20 | — | — | 6:19 | — | — | 6:17 | — | — | 6:16 | — | — | 6:15 | — | — | 6:15 | — | — | 6:14 | — | |
mm | 16 | 6 | 5 | 6 | 2 | 2 | 2 | 2 | 2 | 2 | — | 2 | — | — | 1 | 2 | 2 | 2 | — | — | — |
Temp °C | 27 | 27 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 29 | 28 | 29 | 29 | 29 | 28 | 29 | 28 | 29 | 29 | 28 |
Feels °C | 28 | 29 | 32 | 31 | 29 | 29 | 28 | 27 | 28 | 28 | 30 | 32 | 33 | 33 | 32 | 27 | 27 | 25 | 27 | 27 | 26 |
Swell 1 Height (m) Direction Period (s) | E 18 | E 17 | ENE 16 | ENE 14 | ENE 13 | ENE 12 | NE 12 | NE 12 | NNE 11 | ENE 13 | ENE 12 | S 8 | SSW 9 | SW 9 | SW 10 | SSW 10 | SSW 10 | ENE 12 | SSW 9 | SSW 9 | SSW 9 |
2703 | 3355 | 2305 | 961 | 469 | 187 | 114 | 110 | 51 | 33 | 31 | 367 | 1012 | 899 | 846 | 756 | 833 | 49 | 859 | 865 | 878 | |
Swell 2 Height (m) Direction Period (s) | ENE 10 | SW 8 | SW 9 | SE 9 | ESE 11 | E 15 | ENE 14 | ENE 13 | ENE 13 | NNE 12 | NNE 11 | ENE 12 | ENE 12 | ENE 12 | ENE 13 | ENE 13 | ENE 13 | ENE 12 | E 12 | E 12 | E 11 |
10 | 571 | 594 | 3 | 12 | 17 | 40 | 35 | 34 | 28 | 12 | 28 | 28 | 28 | 69 | 58 | 55 | 83 | 72 | 70 | 63 | |
Swell 3 Height (m) Direction Period (s) | — | ENE 11 | — | SE 9 | — | ESE 11 | E 11 | ESE 10 | ESE 10 | SE 10 | SE 10 | SE 10 | ENE 15 | ENE 15 | SE 9 | E 9 | SE 10 | — | SE 10 | E 10 | E 11 |
— | 12 | — | 3 | — | 11 | 9 | 10 | 10 | 4 | 4 | 4 | 21 | 21 | 3 | 2 | 4 | — | 4 | 2 | 23 | |
Wind waves Height (m) Direction Period (s) | SW 8 | — | — | SW 9 | SW 9 | SW 9 | SW 9 | SW 8 | SW 8 | SW 8 | SW 8 | SW 9 | — | — | — | — | — | SSW 10 | — | — | — |
786 | — | — | 571 | 760 | 585 | 668 | 760 | 702 | 746 | 781 | 528 | — | — | — | — | — | 943 | — | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 14 | 14 | 2 | 14 | 42 | 148 | 316 | 148 | 148 | 316 | 42 | 0 | 2 | 859 | 535 | 693 | 693 | 316 | 693 | 1160 | 348 |
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.











