
Surf Forecasts:
Mainside surf forecast from 11 Sep 2026:
- Best quality surf: Saturday 12 Sep, 9AM (local time) - 2.5ft (0.7m), 7s period, NNW swell with offshore winds.
- Most powerful swell: Wednesday 16 Sep, 3AM (local time) - 2.5ft (0.7m), 9s period, E swell with 85 kJ wave energy.
- Next surfable swell (1★+): Saturday 12 Sep, 9AM (local time) - 2.5ft (0.7m), 7s period with NNW swell.
Best Forecast Surf Conditions for Mainside this week:
The surf forecast for Mainside over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Saturday (Sep 12) at 9AM. The primary swell is predicted to be 0.7m and 7s period. The wind is predicted to be offshore as the swell arrives.
The most powerful waves expected at Mainside in the next 16 days are 0.7m 9s and forecast to arrive on Wednesday (Sep 16) at 3AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.1m 8s period and expected on Monday (Sep 14) at 3AM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9AM (Sat 12th Sep) | 2.5ft (0.7m) 7s |
| Best Surf | 9AM (Sat 12th Sep) | 2.5ft (0.7m) 7s |
| Most Powerful | 3AM (Wed 16th Sep) | 2.5ft (0.7m) 9s |
Table - best surf conditions forecast for Mainside over the next 16 days.
The Lowdown
Alright, Rusty here. Let’s have a look at what’s on the table for Mainside.
Honestly, the next 16 days look pretty average to poor for Mainside. Don't get your hopes up. There's a big gap of nothing good, and the few moments of surfable waves are not going to have you calling in sick.
Looking at Saturday the 12th, we start with some surfable waves but it’s very ordinary. The swell is tiny at only 2ft from the NNW, with a short period of 7 seconds, so it won't have any punch. The wind is offshore from the ESE, keeping things clean, but the waves are weak. The combined swell energy is just 86, really weak. Water temp is 83°, about average for the time of year.
After that, it’s a desert. From Sunday the 13th all the way through Monday the 21st, we have a long stretch of poor surf conditions. Swell stays below 3ft for most of it, with cross-off or cross winds. On Sunday the 20th, things get ugly. We get a jump in swell to 8ft from the east with a 16 second period – that’s a proper groundswell. But the wind is howling from the NNE at 34 mph, creating a total mess. The combined swell energy hits 3296, which is strong, but who cares when it’s a near gale cross-shore? This is kite-surfing territory, not paddle surfing. That kind of wind and size is only for experts, and even then, it’s a battle.
The violent storm force winds on Monday the 21st and the huge, blown-out surf through to Tuesday the 22nd are just dangerous. The swell maxes out at 10ft, and the wind is 71 mph, so don't even think about it.
The only real standout, if you could call it that, would be for experts only during that big swell event around Sunday the 20th of September, but only if they are keen on a beating. The wave direction from the east is not ideal for Mainside’s optimum from the north, so the shape won't be great. The wind is pure evil.
For most of us, this is a blank run. It tends not to stay poor for long around here, but this stretch is a rough one.
Rusty.
Short Range ForecastModerate rain (total 14mm), heaviest on Sun night. Warm (max 29°C on Sat morning, min 27°C on Sat morning). Wind will be generally light. | Days 4-6 Weather SummaryLight rain (total 7mm), mostly falling on Tue afternoon. Warm (max 29°C on Wed afternoon, min 26°C on Thu night). Wind will be generally light. | ||||||||||||||||||||
Saturday 12 | Sunday 13 | Monday 14 | Tuesday 15 | Wednesday 16 | Thursday 17 | Friday 18 | |||||||||||||||
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) | NNW 7 | N 7 | E 14 | E 14 | E 14 | E 13 | E 13 | E 13 | E 9 | E 9 | E 9 | E 9 | E 10 | E 9 | ENE 14 | E 9 | ENE 13 | ENE 13 | E 9 | E 9 | N 7 |
Wave Graph | |||||||||||||||||||||
51 | 45 | 36 | 35 | 36 | 32 | 31 | 30 | 76 | 78 | 83 | 63 | 67 | 63 | 68 | 61 | 34 | 34 | 53 | 36 | 14 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | off | 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-off | cross-off | cross-off | cross-off | cross | cross-off |
High Tide | 8:04PM2.16m | 8:22AM2.19m | 8:30PM2.17m | 8:56AM2.10m | 8:54PM2.14m | 9:30AM1.97m | 9:19PM2.09m | 10:06AM1.82m | 9:44PM2.01m | 10:45AM1.67m | 10:10PM1.90m | 11:36AM1.52m | 10:38PM1.77m | ||||||||
Low Tide | 2:01PM0.39m | 2:15AM0.39m | 2:29PM0.49m | 2:47AM0.36m | 2:56PM0.61m | 3:19AM0.37m | 3:20PM0.75m | 3:52AM0.44m | 3:44PM0.89m | 4:28AM0.53m | 4:08PM1.03m | 5:09AM0.65m | 4:32PM1.18m | ||||||||
6:13 | — | — | 6:13 | — | — | 6:13 | — | — | 6:13 | — | — | 6:13 | — | — | 6:15 | — | — | 6:15 | — | — | |
— | 6:37 | — | — | 6:36 | — | — | 6:35 | — | — | 6:34 | — | — | 6:32 | — | — | 6:31 | — | — | 6:30 | — | |
mm | — | — | — | — | 3 | 6 | — | 3 | 2 | — | 2 | 1 | 1 | 1 | 1 | 1 | — | — | — | — | — |
Temp °C | 29 | 29 | 27 | 29 | 29 | 27 | 28 | 29 | 27 | 28 | 28 | 27 | 28 | 29 | 27 | 28 | 29 | 27 | 29 | 28 | 27 |
Feels °C | 33 | 32 | 30 | 31 | 31 | 30 | 32 | 32 | 30 | 31 | 31 | 30 | 32 | 32 | 29 | 31 | 32 | 29 | 31 | 29 | 29 |
Swell 1 Height (m) Direction Period (s) | NNW 7 | N 7 | N 6 | ESE 5 | ESE 7 | N 5 | ESE 8 | ESE 9 | E 9 | E 9 | E 9 | E 9 | E 10 | E 9 | NNW 6 | E 9 | E 9 | E 9 | N 6 | E 9 | E 8 |
51 | 45 | 20 | 11 | 34 | 9 | 75 | 79 | 76 | 78 | 83 | 63 | 67 | 63 | 32 | 61 | 42 | 40 | 12 | 36 | 37 | |
Swell 2 Height (m) Direction Period (s) | SE 6 | SE 6 | E 14 | NNW 6 | E 14 | E 13 | N 5 | E 13 | E 13 | ENE 13 | NNW 6 | NNW 5 | NNW 6 | NNW 6 | E 9 | N 6 | N 6 | N 7 | ENE 12 | N 8 | N 7 |
18 | 8 | 36 | 12 | 36 | 32 | 5 | 30 | 31 | 33 | 7 | 5 | 16 | 17 | 64 | 19 | 17 | 22 | 30 | 18 | 14 | |
Swell 3 Height (m) Direction Period (s) | E 14 | E 14 | SE 6 | E 14 | NNW 6 | S 6 | E 13 | N 5 | N 5 | NW 7 | E 12 | ENE 12 | ENE 14 | ENE 14 | ENE 14 | ENE 14 | ENE 13 | ENE 13 | S 8 | ENE 12 | ENE 12 |
35 | 36 | 5 | 35 | 3 | 1 | 31 | 5 | 2 | 2 | 27 | 30 | 40 | 37 | 68 | 38 | 34 | 34 | 6 | 14 | 14 | |
Wind waves Height (m) Direction Period (s) | SE 6 | — | E 3 | ENE 3 | NE 4 | ESE 8 | — | — | — | — | — | — | — | — | ENE 3 | — | — | ENE 3 | E 9 | — | NE 4 |
49 | — | 3 | 4 | 10 | 67 | — | — | — | — | — | — | — | — | 1 | — | — | 1 | 53 | — | 6 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 0 | 0 | 13 | 13 | 13 | 608 | 25 | 25 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 13 | 1 | 650 | 13 |
Best forecast wave conditions in Okinawa | |||||||||||||||||||||
Best forecast wave conditions in Japan | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)
Wind Speed (km/h)
Information about the Mainside Surf forecast
The above surf forecast table for Mainside provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Mainside can be found by selecting the local surf guide option on the grey menu. Our Mainside 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 (Mainside) 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 Mainside 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.
Mainside is 11 km (7 miles) from the city of Ishikawa. If you plan a holiday in Okinawa, look for hotels and other accommodation in Ishikawa. Ishikawa has rooms for a wide range of budgets as well as car hire and transport links.










