Surf forecastStatisticsHistorical report

The Alley seasonal overview

Best Surf Season (March - May)

As the Australian summer heat wanes and the synoptic scale begins its dramatic shift, the months of March through May deliver the most consistent blend of quality swell and favorable wind at The Alley. During this window, the dominant southward migration of the subtropical ridge brings more frequent passages of cold fronts, generating swell trains from the E to ENE that wrap nicely into the northeast-facing beach. Simultaneously, the fading of the summer monsoon and the onset of strong, persistent high pressure south of the continent drive increasing percentages of offshore wind from the SSW to W—peaking at 62% in May. Average wave heights hover around a solid 1.1 to 1.2m with periods of 8.5 to 8.8s, producing punchy, rippable walls. This is prime time for The Alley, when the combination of power and clean conditions aligns most often.

Fair Surf Season (December - February & June - August)

Surf during the summer and winter shoulder months is a mixed bag. From December to February, the summer regime pumps consistent trade-swell from the E and ENE, with average heights of 1.0 to 1.2m and periods of 7.5 to 8.4s. However, the trade winds themselves blow from the same directions (NE to E) and directly spoil the wave face, limiting ideal offshore wind to just 23-29% of the time. The result is plenty of swell but often choppy, onshore conditions. Conversely, from June to August, the winter pattern delivers the highest offshore wind percentages—reaching 63-66%—but swell heights drop to 0.9-1.0m as the fetch of the easterly trades weakens. The waves become smaller and more inconsistent, though when a proper winter swell from the deep south or a rare easterly pulse arrives, the near-perfect offshore flow can turn the beach into a long, clean playground. Those willing to check the forecast during these seasons will find windows of excellence, but persistence is required.

Low Surf Season (September - November)

Spring is the least reliable period for The Alley. As the subtropical ridge weakens and transitions toward its summer position, the region falls into a meteorological no-man's land. The average swell height dips to just 0.9-1.0m, periods slide to 7.3-7.8s, and ideal offshore wind drops to 24-39% of the time. The wind roses show a strong encroachment of northerly and northeasterly flows (N, NNE, NE) that are both onshore and detrimental to wave quality. Swell direction remains heavily skewed toward the E and ESE, but the lack of period and the persistent onshore breezes often turn even moderate swell into lumpy, unappealling surf. While a rogue cold front or strong low can briefly fire things up, these months are generally best left for those with low expectations or a quiver of grovelers—wait until the autumn stability returns for true quality at The Alley.

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Conditions at The Alley in December

December: Summer Arrives, Trade Swell Returns

December marks the return of the summer pattern. The average swell height is 1.0m with a period of 7.5s, signaling the dominance of short-period trade wind swell. The swell direction is heavily skewed toward the E (28.4%), ENE (20%), and ESE (18.7%), with NNE (8.7%) and NE (11.8%) also contributing. All of these are optimal for the beach, meaning the wave window is wide open. However, the wind quality remains subpar—ideal offshore conditions occur only 24% of the time, tied with November for the lowest. Onshore winds from N (13.6%), NNE (9.7%) and NE (5.9%) are common, as the strong southeast trade winds blow directly in the face of the swell. The wind rose also shows a significant SSE (11.3%) and SE (10.5%) component, which is sideshore but often gusty. December is a month of abundant swell but marginal conditions. When a brief westerly change or a local seabreeze suppression event occurs, the trade swell can clean up into fun, rippable 1-1.5m waves. But for the most part, expect choppy, onshore conditions. It’s a month for those who don’t mind a little texture in their surf, or for kite and windsurfers who thrive in the strong winds.

Average Spot conditions at The Alley in December

Swell history for December

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

Wind history for December

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

Swell quality

Analyze the groundswell consistency at The Alley during December. 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 The Alley for your next trip in December.

Ground swell

Ground swell by size

Wind conditions

Evaluate the wind and swell alignment at The Alley for December. 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 The Alley.

Swell with good wind

Swell with good wind by size