Surf Forecasts:
The Rock surf forecast from 18 Aug 2026:
- Most powerful swell: Tuesday 18 Aug, 2PM (local time) - 7ft (2.2m), 19s period, SSW swell with 3,412 kJ wave energy.
Best Forecast Surf Conditions for The Rock this week:
The most powerful waves expected at The Rock in the next 16 days are 2.2m 19s and forecast to arrive on Tuesday (Aug 18) at 2PM. Winds are predicted to be cross-shore at the time the swell arrives.
| Wave Type | Time (+0530) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 2PM (Tue 18th Aug) | 7ft (2.2m) 19s |
Table - best surf conditions forecast for The Rock over the next 16 days.
The Lowdown
Alright, surfer, Rusty here. Let’s have a look at what the ocean’s got cookin’ for us. We’ve got a solid stretch of groundswell lining up, but it’s not all gonna be clean. The main story is a decent SSW pulse that’s gonna run for a bit, but the local winds are gonna be the thing that sorts the men from the boys. It’s not gonna be a total washout, but you’re gonna have to pick your moments.
The first window of real interest is Tuesday, August 18th. The Rock (Kabalana) is breaking at 7ft. This is a strong SSW groundswell with a long 19-second period. The energy is strong, we’re talking 3824 on the dial. The water’s sitting at 82°, which is about average for this time of year. The morning has a risk of tstorms and a cross-shore W wind at 12 mph, which will kick up a bit of a cross-chop. Honestly, it looks a bit messy and marginal. It’s surfable for sure, but not the cleanest.
The swell holds through Wednesday, August 19th, but the wind swings more cross-on from the W. The energy actually builds to 4753 by the afternoon, but the chop is gonna make it tricky. Unless you’re really keen, this day looks like a fight. Thursday the 20th sees the swell ease a little to 6ft with a 16-second period. Still a lot of energy (2041), but the wind stays cross-shore. It’s still marginal.
The surf stays in the 4ft to 5ft range through Friday and Saturday, with the period dropping to 14-15 seconds. The energy is dropping too, down to around the 1000 mark. Still cross-shore winds and a bit of chop. These are the days for the longboard or a funboard, just to get wet. It’s not gonna be epic.
Now, there’s a serious gap of poor conditions from Sunday the 23rd through to the end of the month. The swell drops, the winds get messier, and the forecast is calling out "poor surf conditions" on a few days. Sunday the 30th and Monday the 31st bring a little more size back (5ft to 5ft) but the energy jumps, and the wind remains problematic. It’s just not coming together cleanly.
But hold on, don’t write it off yet. The standout of the entire run is looking like Tuesday, September 1st. We’ve got a solid SSW swell pushing back up to 7ft, with a 16-second period. The energy is strong at 2707. The wind is still W at 16 mph in the morning, but it’s cross-shore, not onshore. It’s gonna be a bigger, more powerful day at The Rock. This is the pick of the week, but it’s a week out, so take it with a grain of salt. Long-range calls are always a bit of a gamble.
So, there you have it. The next few days are all about catching the energy early before the wind messes it up. The real gem is that September 1st window if the forecast holds. You got a week to get your quiver ready for that one.
Stay salty.
Rusty.
Short Range ForecastModerate rain (total 15mm), heaviest on Tue morning. Warm (max 28°C on Tue morning, min 26°C on Tue morning). Wind will be generally light. | Days 4-6 Weather SummaryModerate rain (total 16mm), heaviest on Sat night. Warm (max 28°C on Fri morning, min 26°C on Fri night). Wind will be generally light. | ||||||||||||||||||||
Tuesday 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | |||||||||||||||
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 19 | SSW 19 | SSW 18 | SSW 17 | SSW 18 | SSW 16 | SSW 16 | SSW 16 | SSW 15 | S 14 | SSW 14 | S 17 | S 15 | S 15 | S 14 | S 14 | S 13 | SSW 18 | SSW 18 | SSW 16 | SSW 16 |
Wave Graph | |||||||||||||||||||||
3448 | 3306 | 2897 | 2832 | 3056 | 2458 | 1938 | 1643 | 1168 | 965 | 704 | 562 | 544 | 636 | 569 | 736 | 591 | 422 | 510 | 669 | 1038 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross | cross | cross-on | cross | cross | cross | cross | cross | cross | cross | cross | cross-on | cross | cross | cross-on | cross | cross | cross-on | cross | cross |
High Tide | 4:56PM0.44m | 5:32AM0.47m | 5:15PM0.39m | 5:55AM0.43m | 5:26PM0.34m | 6:22AM0.38m | 5:04PM0.29m | 7:36AM0.33m | 2:42AM0.29m | 12:36PM0.37m | 1:45AM0.33m | 1:06PM0.42m | 1:50AM0.37m | ||||||||
Low Tide | 11:11AM0.13m | 11:05PM0.07m | 11:36AM0.16m | 11:22PM0.12m | 12:03PM0.21m | 11:32PM0.17m | 12:40PM0.26m | 11:10PM0.22m | 8:20PM0.22m | 6:07AM0.27m | 7:39PM0.17m | 6:55AM0.22m | 7:46PM0.13m | ||||||||
6:03 | — | — | 6:03 | — | — | 6:03 | — | — | 6:03 | — | — | 6:03 | — | — | 6:03 | — | — | 6:01 | — | — | |
— | 6:21 | — | — | 6:21 | — | — | 6:20 | — | — | 6:20 | — | — | 6:19 | — | — | 6:19 | — | — | 6:19 | — | |
mm | 3 | — | 1 | 2 | — | 3 | 2 | — | 4 | 1 | — | 2 | — | — | 5 | 2 | 2 | 4 | 1 | — | — |
Temp °C | 28 | 28 | 27 | 28 | 28 | 27 | 28 | 28 | 27 | 28 | 28 | 27 | 28 | 28 | 26 | 28 | 28 | 26 | 28 | 28 | 26 |
Feels °C | 29 | 29 | 30 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 28 | 30 | 29 | 28 | 29 | 30 | 29 | 29 | 29 | 29 | 28 |
Swell 1 Height (m) Direction Period (s) | SSW 19 | SSW 19 | SSW 18 | SSW 17 | SSW 18 | SSW 16 | SSW 16 | SSW 16 | SSW 15 | S 14 | SSW 14 | S 12 | S 15 | S 15 | S 14 | S 14 | S 13 | S 13 | S 12 | SSW 12 | SSW 16 |
3448 | 3306 | 2897 | 2832 | 3056 | 2458 | 1938 | 1643 | 1168 | 965 | 704 | 333 | 544 | 636 | 569 | 736 | 591 | 404 | 290 | 367 | 1038 | |
Swell 2 Height (m) Direction Period (s) | W 9 | SSE 10 | SSE 9 | S 19 | S 18 | W 8 | W 9 | W 10 | W 10 | W 10 | S 18 | S 17 | S 11 | S 10 | S 10 | S 21 | S 20 | SSW 18 | SSW 18 | SSW 16 | WNW 10 |
139 | 80 | 66 | 900 | 1615 | 51 | 63 | 46 | 31 | 31 | 240 | 562 | 223 | 218 | 151 | 233 | 276 | 422 | 510 | 669 | 86 | |
Swell 3 Height (m) Direction Period (s) | SSE 10 | — | S 21 | W 9 | — | — | — | — | S 24 | S 22 | W 9 | SSW 13 | S 18 | S 26 | W 6 | W 11 | WNW 10 | W 10 | W 10 | SW 16 | — |
107 | — | 323 | 57 | — | — | — | — | 11 | 36 | 28 | 59 | 221 | 13 | 57 | 9 | 36 | 32 | 32 | 64 | — | |
Wind waves Height (m) Direction Period (s) | W 6 | W 6 | W 9 | W 6 | W 6 | WSW 6 | W 6 | W 6 | W 6 | W 6 | W 6 | W 6 | W 6 | W 6 | W 6 | W 6 | W 6 | WSW 5 | WSW 5 | W 10 | W 10 |
130 | 119 | 169 | 80 | 82 | 83 | 101 | 110 | 80 | 108 | 86 | 67 | 95 | 78 | 89 | 52 | 42 | 37 | 45 | 122 | 125 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 193 | 763 | 374 | 192 | 374 | 193 | 192 | 192 | 369 | 192 | 374 | 193 | 192 | 875 | 193 | 192 | 763 | 193 | 189 | 374 | 193 |
Best forecast wave conditions in West Sri Lanka | |||||||||||||||||||||
Best forecast wave conditions in Sri Lanka | |||||||||||||||||||||
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Information about the The Rock Surf forecast
The above surf forecast table for The Rock provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at The Rock can be found by selecting the local surf guide option on the grey menu. Our The Rock 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 (The Rock) 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 The Rock 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.











