Surf forecastStatisticsHistorical report

Dee Why Point seasonal overview

Best Surf Season (May - August)

This is when the winter engine of the Tasman Sea really kicks into gear. High-latitude low-pressure systems deepen off the southeast coast of Australia, firing up long-period S to SSE swells that wrap beautifully into Dee Why Point. Simultaneously, the offshore wind window widens dramatically: with more than 44% of the time seeing clean W to SW flow (ideal for this east-facing setup), the point often delivers groomed, powerful waves. Periods average 9.5-9.7 seconds, pushing the swell into the 'punchy to powerful' range, and heights sit consistently in the 1.5-2.5m range – solid, rippable, and at times truly pumping. Late autumn and winter are the prime, no doubt about it.

Fair Surf Season (March, April, September, October)

As the transition seasons set in, the climate patterns become more fickle. The subtropical ridge starts shifting, and the frequency of strong southerly swells begins to ebb or ramp up. March and April still see a decent share of S/SE swell, and wind quality improves as the months progress – April hits 33% ideal wind – so you can still score clean, fun waves on the right days. September and October bring the first southern spring storms, but also more interference from weakening summer patterns. Swell heights hold up around 1.6-1.7m, but the periods dip slightly compared to winter. When a south swell lines up with a land-based westerly, the point still turns on, but you will have to pick your windows carefully.

Low Surf Season (November - February)

Summer snuffs out the long-period groundswells. The south swell corridor goes quiet as the storm tracks retreat toward Antarctica, and the dominant swell shifts to short-period, choppy E and NE pulses generated by local sea breezes and tropical easterly trades. Periods average only 8.3-8.8 seconds, resulting in weak, crumbly waves unless a cyclone wanders south. Even worse, the onshore winds rule – NE to E breezes spoil the surface more than 85% of the time, making conditions sloppy and bumpy. Ideal offshore flow from the west drops to just 12-15%. A few fleeting windows open when a ridge builds offshore, but for the most part, this is the time to schedule gear repairs and wait for autumn.

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Conditions at Dee Why Point in September

September: Spring Transition Begins

Spring arrives, and with it comes a change in the pattern. The average swell stays at 1.6m, but the period drops slightly to 9.0 seconds – still rideable but losing some of that winter grunt. Swell direction becomes more mixed: SSE and S remain the largest contributors (over 33% combined), but NE and ENE swells are now more prominent (over 18% combined). This indicates the first signs of tropical influences and a less stable storm track. Wind quality falls to 34% ideal – still decent but not as reliable as winter. The offshore flow from W and WSW is still common, but the onshore NNE/N winds are picking up strength and frequency (over 14% combined at 10-30+kph). The best opportunities come from strong southerly fronts that sweep through with a rapid wind shift to the west. These frontal passages deliver a few days of powerful, clean surf before the wind relaxes and goes NE again. Be ready to move quickly when a cold front approaches.

Average Spot conditions at Dee Why Point in September

Swell history for September

0 - 0.5
0.5 - 1
1 - 1.5
1.5 - 2.0
2.0 - 2.5
> 2.5 m

Wind history for September

0 - 10
10 - 20
20 - 30
30 - 40
40 - 50
> 50 km/h

Swell quality

Analyze the groundswell consistency at Dee Why Point during September. Based on historical data, there is a % probability of groundswell occurring this month. The chart below provides a detailed breakdown of the average wave height distribution, offering deep insights into the swell quality and surf potential you can expect at Dee Why Point for your next trip in September.

Ground swell

Ground swell by size

Wind conditions

Evaluate the wind and swell alignment at Dee Why Point for September. Our analysis shows that favorable offshore or side-shore winds coincide with surfable swell approximately % of the time. The accompanying graph illustrates the average size distribution of waves during these optimal wind windows at Dee Why Point.

Swell with good wind

Swell with good wind by size