Surf Forecasts:
Backdoor surf forecast from 15 Sep 2026:
- Best quality surf: Monday 14 Sep, 11PM (local time) - 1ft (0.3m), 21s period, SW swell with cross-offshore winds.
- Most powerful swell: Thursday 17 Sep, 2AM (local time) - 5ft (1.6m), 6s period, NE swell with 195 kJ wave energy.
- Next surfable swell (1★+): Monday 14 Sep, 11PM (local time) - 1ft (0.3m), 21s period with SW swell.
Best Forecast Surf Conditions for Backdoor this week:
The surf forecast for Backdoor over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Monday (Sep 14) at 11PM. The primary swell is predicted to be 0.3m and 21s period with a secondary swell of 0.7m and 8s. Another secondary swell of 0.3m and 13s is also forecast. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Backdoor in the next 16 days are 1.6m 6s and forecast to arrive on Thursday (Sep 17) at 2AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 2.3m 8s period and expected on Thursday (Sep 17) at 2PM.
| Wave Type | Time (HST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 11PM (Mon 14th Sep) | 1ft (0.3m) 21s |
| Best Surf | 11PM (Mon 14th Sep) | 1ft (0.3m) 21s |
| Most Powerful | 2AM (Thu 17th Sep) | 5ft (1.6m) 6s |
Table - best surf conditions forecast for Backdoor over the next 16 days.
The Lowdown
Alright, let’s get to the good stuff. Monday the 28th of September is the day. Backdoor—a reef break with a proper reputation—lights up. The swell comes from the NE at a clean 2.1m with an 8-second period. That’s more than 2.5m, so this one’s for experienced surfers only; too big for beginners. Combined wave energy hits a strong 691 to 656, so there’s plenty of grunt in the water. The wind swings to a gentle offshore breeze from the ESE at 15 km/h, giving us clean, lined-up faces. It’s an exposed break, and the swell direction from the NE matches the optimum NW direction pretty well, so it’s gonna hold that energy.
Tuesday the 29th of September is the cherry on top. The morning is glassy—ESE wind dropping to just 5 km/h, with the swell still pushing a solid 2.1m from the NE, 8-second period, and combined energy at a massive 722. That’s glassy, clean, and powerful. Afternoon drops off to a smaller 0.7m from the NNE with a longer 11-second period and only 116 energy, but the morning window is your absolute best bet.
Water temperature sits at 27° with no anomaly, so it’s about average for this time of year. The crowd profile for Backdoor is marked as “often,” so expect company, especially with a standout day like this.
The rest of the outlook fades after Tuesday the 29th afternoon, with the Thursday the 24th at 0.5m and 163 energy being surfable but far from special.
You’ve got one true standout here: the morning of Tuesday the 29th of September at Backdoor. Glassy conditions, solid 2.1m NE swell, and powerful energy. That’s the one to circle.
Stay patient, and keep an eye on the charts. Rusty.
Short Range ForecastMostly dry. Warm (max 27°C on Tue morning, min 25°C on Mon night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 4mm), mostly falling on Thu afternoon. Warm (max 27°C on Thu afternoon, min 25°C on Thu night). Wind will be generally light. | |||||||||||||||||||
Mon 14 | Tuesday 15 | Wednesday 16 | Thursday 17 | Friday 18 | Saturday 19 | Sunday 20 | ||||||||||||||
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) | NE 8 | SW 21 | SW 20 | NE 8 | SW 19 | SW 18 | WNW 10 | NE 6 | SW 16 | SW 16 | NW 12 | NW 10 | NW 10 | NW 9 | W 9 | SW 16 | N 12 | N 11 | N 11 | W 12 |
Wave Graph  | ||||||||||||||||||||
 kJ | 80 | 72 | 188 | 128 | 181 | 152 | 9 | 195 | 125 | 125 | 5 | 4 | 4 | 3 | 3 | 122 | 4 | 10 | 9 | 12 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | 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-off | cross-off | cross-off | cross-off | cross-off |
High Tide | 3:14PM0.49m | 5:33AM0.61m | 2:56PM0.46m | 6:37AM0.59m | 8:23AM0.57m | 10:24AM0.59m | 11:23AM0.62m | 11:59AM0.65m | 11:14PM0.30m | |||||||||||
Low Tide | 10:01PM0.12m | 11:37AM0.42m | 10:21PM0.13m | 10:44PM0.15m | 11:15PM0.18m | 00:18AM0.21m | 2:58AM0.22m | 8:12PM0.28m | ||||||||||||
 |  | | | | | |  |  |  |  | | | | | | | | | | |
 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:18 | — | — | 6:20 | — | — | 6:20 | — | — |
 | 6:36 | — | — | 6:35 | — | — | 6:34 | — | — | 6:32 | — | — | 6:31 | — | — | 6:30 | — | — | 6:30 | — |
mm | — | — | — | — | — | — | — | — | — | 1 | 3 | — | — | — | — | — | — | — | — | — |
Temp °C | 26 | 25 | 27 | 27 | 26 | 27 | 27 | 26 | 26 | 27 | 26 | 27 | 27 | 26 | 26 | 27 | 26 | 26 | 26 | 26 |
Feels °C | 26 | 26 | 29 | 28 | 28 | 27 | 27 | 26 | 26 | 27 | 26 | 26 | 26 | 26 | 26 | 27 | 26 | 26 | 25 | 26 |
Swell 1 Height (m) Direction Period (s) | NE 8 | NE 8 | SW 20 | E 12 | NNE 7 | SW 18 | SSW 18 | E 10 | SW 16 | SW 16 | SSW 17 | SSW 17 | SSW 17 | SSW 16 | SSW 16 | SW 16 | SSW 16 | SSW 15 | SSW 15 | SSW 14 |
| kJ | 80 | 67 | 188 | 44 | 48 | 152 | 207 | 96 | 125 | 125 | 202 | 202 | 193 | 173 | 166 | 122 | 95 | 86 | 84 | 82 |
Swell 2 Height (m) Direction Period (s) | SW 22 | SW 21 | E 12 | SSW 19 | SW 19 | SSW 12 | WNW 10 | SW 17 | SW 11 | SSW 20 | NW 12 | NW 10 | NW 10 | NW 9 | NW 8 | NW 10 | NW 10 | N 11 | NW 9 | NNW 10 |
| kJ | 119 | 72 | 26 | 148 | 181 | 13 | 9 | 145 | 18 | 37 | 5 | 4 | 4 | 3 | 3 | 4 | 4 | 10 | 3 | 11 |
Swell 3 Height (m) Direction Period (s) | SSW 14 | SSW 13 | SSW 13 | SSW 12 | E 11 | SW 8 | SSW 11 | SW 11 | SSW 20 | SW 8 | SW 10 | W 9 | W 9 | W 9 | W 9 | S 18 | N 12 | NW 9 | N 11 | W 12 |
| kJ | 18 | 17 | 16 | 15 | 58 | 3 | 12 | 19 | 38 | 3 | 4 | 2 | 2 | 2 | 1 | 6 | 3 | 3 | 9 | 12 |
Wind waves Height (m) Direction Period (s) | ENE 4 | ENE 4 | NE 8 | NE 8 | E 5 | ENE 10 | ENE 10 | NE 6 | ENE 7 | ENE 8 | ENE 9 | ENE 8 | E 8 | E 8 | E 8 | E 8 | E 8 | ENE 8 | ENE 8 | ENE 7 |
| kJ | 15 | 15 | 113 | 128 | 40 | 325 | 386 | 195 | 503 | 737 | 708 | 437 | 453 | 464 | 422 | 428 | 476 | 416 | 416 | 375 |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 2 | 1 | 2 | 2 | 2 | 24 | 150 | 24 | 24 | 5 | 24 | 24 | 24 | 24 | 24 | 2 | 24 | 24 | 24 | 24 |
Best forecast wave conditions in Oahu | ||||||||||||||||||||
Best forecast wave conditions in United States | ||||||||||||||||||||
Header Global | ||||||||||||||||||||
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The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Backdoor surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.
Information about the Backdoor Surf forecast
The above surf forecast table for Backdoor provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Backdoor can be found by selecting the local surf guide option on the grey menu. Our Backdoor 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 (Backdoor) 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 Backdoor 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.
Backdoor is 19 km (12 miles) from Wahiawa. If you plan a vacation in Oahu, look for hotels and other accommodation in Wahiawa. Wahiawa has rooms for a wide range of budgets as well as car hire and transport links.
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