
Surf Forecasts:
Nai Harn Beach surf forecast from 9 Sep 2026:
- Most powerful swell: Thursday 17 Sep, 7AM (local time) - 11ft (3.5m), 9s period, W swell with 1,716 kJ wave energy.
Best Forecast Surf Conditions for Nai Harn Beach this week:
The most powerful waves expected at Nai Harn Beach in the next 16 days are 3.5m 9s and forecast to arrive on Thursday (Sep 17) at 7AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.4m 7s period and expected on Wednesday (Sep 16) at 4AM.
| Wave Type | Time (+07) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 7AM (Thu 17th Sep) | 11ft (3.5m) 9s |
Table - best surf conditions forecast for Nai Harn Beach over the next 16 days.
The Lowdown
Alright, Rusty here. Let's have a look at what's cookin' for Nai Harn Beach.
Honestly, mate, it's a rough stretch ahead. We're looking at a solid 16-day window, and I gotta be straight with you—there's not a single surfable day in the bunch. The whole period is a write-off, and that's a tough pill to swallow for an area that can be fairly consistent. But sometimes the cards just fall that way, and forecasts can change, so don't bin the boards just yet.
The first few days, from Thursday the 10th through to the 16th, are just a mess of cross-shore and onshore winds, lumpy chop, and weak, mostly short-period windswell. The energy is pitiful, with combined swell energy typically in the low triple digits (117 to 161) or even lower, and the wave heights are barely a ripple on the best days. It’s a total non-starter.
Then, from the 17th of September, things get angry. A real pulse of swell rolls in, with heights pushing 10ft to 13ft and combined energy spiking into the thousands (1782, 2731). That sounds like it could be something, but it’s all coming in with howling onshore winds—strong breeze and near-gale force—smashing the surface into a white, blown-out mess. For a beach and reef setup like Nai Harn, this is more of a kite-surfing dream than a paddling one. The swell is too big for beginners, and even for the crew, it’s just unsurfable junk.
After that, the swell drops off through the 20th and 21st, but the winds don't let up. It stays messy and cross-onshore, with energy dropping from 494 down to 211. The tail end of the window, around the 24th and 25th, sees a slight improvement in the wind direction coming from the SE and SSE, going cross-shore, but the swell is tiny at 3ft to 3ft with a short period of 9 seconds. The combined energy is weak (118 to 188), and it just won't have enough push to break cleanly.
So, there it is. A long, blank stretch with no standout, no hidden gem, not even a half-decent window. It’s just one of those periods where the ocean is telling you to take a week off.
Rusty.
Short Range ForecastModerate rain (total 16mm), heaviest on Sat afternoon. Warm (max 29°C on Wed night, min 28°C on Thu night). Mainly fresh winds. | Days 4-6 Weather SummaryHeavy rain (total 94mm), heaviest during Mon morning. Warm (max 27°C on Sat night, min 25°C on Sat night). Wind will be generally light. | ||||||||||||||||||||
Thursday 10 | Friday 11 | Saturday 12 | Sunday 13 | Monday 14 | Tuesday 15 | Wednesday 16 | |||||||||||||||
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) | WSW 16 | WNW 6 | WNW 6 | W 6 | WNW 6 | WNW 6 | WNW 5 | WSW 21 | WSW 20 | WSW 19 | WSW 19 | WSW 18 | WSW 17 | WSW 17 | WSW 16 | WSW 16 | WSW 16 | WSW 15 | W 6 | W 6 | W 8 |
Wave Graph | |||||||||||||||||||||
25 | 108 | 89 | 82 | 83 | 67 | 48 | 90 | 75 | 125 | 122 | 102 | 101 | 54 | 50 | 50 | 49 | 22 | 100 | 94 | 617 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross | cross | cross | cross | cross | cross-on | cross-off | cross-on | on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | on | on | cross-on |
High Tide | 9:56AM1.96m | 10:25PM1.83m | 10:31AM2.01m | 10:57PM1.92m | 11:04AM2.00m | 11:26PM1.96m | 11:34AM1.94m | 11:55PM1.95m | 12:03PM1.84m | 00:22AM1.90m | 12:31PM1.70m | 00:49AM1.81m | 12:58PM1.55m | 1:16AM1.69m | |||||||
Low Tide | 4:16PM0.01m | 4:23AM0.13m | 4:47PM-0.05m | 4:58AM0.08m | 5:16PM-0.05m | 5:30AM0.07m | 5:43PM-0.00m | 6:02AM0.11m | 6:09PM0.09m | 6:32AM0.20m | 6:33PM0.20m | 7:01AM0.31m | 6:57PM0.34m | ||||||||
6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | 6:16 | — | — | |
— | 6:30 | — | — | 6:29 | — | — | 6:28 | — | — | 6:28 | — | — | 6:27 | — | — | 6:27 | — | — | 6:25 | — | |
mm | — | 1 | 2 | 3 | 2 | 2 | 2 | 3 | 11 | 3 | 3 | 28 | 20 | 10 | 4 | 9 | 6 | 12 | 9 | 9 | 9 |
Temp °C | 29 | 29 | 29 | 29 | 29 | 28 | 28 | 28 | 27 | 26 | 26 | 25 | 26 | 26 | 27 | 27 | 27 | 27 | 28 | 28 | 28 |
Feels °C | 29 | 29 | 29 | 30 | 29 | 28 | 29 | 28 | 29 | 26 | 26 | 25 | 26 | 26 | 27 | 28 | 29 | 27 | 31 | 27 | 26 |
Swell 1 Height (m) Direction Period (s) | WSW 16 | SW 15 | WSW 15 | WSW 15 | WSW 15 | WSW 16 | WSW 22 | WSW 21 | WSW 20 | W 5 | W 5 | WSW 18 | W 5 | W 5 | WNW 7 | WNW 7 | WNW 6 | WSW 15 | W 6 | WSW 9 | — |
25 | 9 | 21 | 22 | 22 | 25 | 45 | 90 | 75 | 32 | 24 | 102 | 19 | 13 | 15 | 15 | 8 | 22 | 100 | 8 | — | |
Swell 2 Height (m) Direction Period (s) | — | — | — | W 26 | W 26 | W 24 | WSW 16 | WSW 16 | WSW 15 | WSW 19 | SSE 5 | SSE 4 | WSW 17 | WSW 17 | WSW 16 | WSW 16 | WSW 16 | W 11 | WSW 10 | WSW 15 | — |
— | — | — | 13 | 13 | 43 | 25 | 25 | 21 | 125 | 9 | 4 | 101 | 54 | 50 | 50 | 49 | 9 | 10 | 21 | — | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | SW 16 | S 6 | WSW 19 | W 7 | — | — | WSW 16 | — | W 12 | — | WSW 15 | — | — |
— | — | — | — | — | — | — | — | 10 | 3 | 122 | 8 | — | — | 25 | — | 3 | — | 21 | — | — | |
Wind waves Height (m) Direction Period (s) | WNW 6 | WNW 6 | WNW 6 | W 6 | WNW 6 | WNW 6 | WNW 5 | WNW 5 | WNW 5 | W 5 | SW 5 | W 5 | — | W 5 | W 7 | — | WSW 2 | W 6 | — | W 6 | W 8 |
95 | 108 | 89 | 82 | 83 | 67 | 48 | 46 | 31 | 12 | 12 | 28 | — | 4 | 8 | — | 1 | 124 | — | 94 | 617 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 635 | 636 | 635 | 635 | 217 | 106 | 635 | 4 | 108 | 4 | 635 | 635 | 4 | 4 | 635 | 4 | 4 | 24 | 24 | 601 | 636 |
Best forecast wave conditions in Phuket | |||||||||||||||||||||
Best forecast wave conditions in Thailand | |||||||||||||||||||||
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Information about the Nai Harn Beach Surf forecast
The above surf forecast table for Nai Harn Beach provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Nai Harn Beach can be found by selecting the local surf guide option on the grey menu. Our Nai Harn Beach 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 (Nai Harn Beach) 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 Nai Harn Beach 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.
Nai Harn Beach is 8 km (5 miles) from the city of Ban Chalong. If you plan a holiday in Phuket, look for hotels and other accommodation in Ban Chalong. Ban Chalong has rooms for a wide range of budgets as well as car hire and transport links.










