Surf forecastStatisticsHistorical report

Nalvo seasonal overview

Best Surf Season (November - February)

During the peak of the Northeast Monsoon, Nalvo comes alive with consistent swell and favorable wind patterns. From November through February, the South China Sea is churned by powerful extratropical storms and the strengthening trade winds, sending pulses of medium to long-period groundswell toward the Philippine west coast. The average wave height hovers around 1.0-1.2m with periods in the 7.7-8.0s range, providing punchy, rideable surf that often holds enough power for carves and cutbacks. Crucially, the ideal wind frequency peaks at 52-59% during these months, with offshore flow from the east and northeast (blowing from land to sea) ensuring clean, well-shaped faces. While the dominant swell direction is from the north and north-northeast—angles that aren't perfect for this west-facing setup—the energy wraps around the island's northern points and lines up nicely along the beach. When a true west-northwest to northwest swell aligns with clear skies and light offshore winds, Nalvo delivers its best, most rippable conditions.

Fair Surf Season (March & October)

Shoulder months offer a mixed bag: October sees the transition from the Southwest Monsoon to the Northeast Monsoon, with average swell heights rising to 1.1m and periods of 7.7s. The ideal wind frequency climbs to 44%, offering more clean days than summer. March is the tail end of the NE Monsoon, with decreasing swell averages (0.7m) and periods dropping to 6.6s, but still 31% offshore wind odds. In both months, the swell window opens up to include more westerly energy—particularly October, where WNW and NW swells become more common—making for fun, sometimes excellent sessions when the synoptics align. Expect a mix of clean, rippable banks and occasional wind-affected days.

Low Surf Season (April - September)

The Southwest Monsoon dominates from June through September, bringing persistent southerly to southwesterly winds that are largely onshore for Nalvo's west-facing lineup. While the swell regime shifts to a higher percentage of optimal SSW and SW swell directions (especially June-August, where SW swell makes up over 40% of the spectrum), the accompanying wind is almost always from the south quadrant, often blowing 10-20 kph and ruining surface quality. Average wave heights are modest—0.5m in May, climbing to 0.9-1.1m in June-August—and wave periods remain in the 5.7-7.0s range, producing mostly short-period, messy surf. Ideal wind frequency drops to 15-28%, meaning that clean, glassy conditions are rare exceptions. April and May are the doldrums, with minimal swell and weak wind patterns. The few rideable days occur when a tropical cyclone in the South China Sea generates SSW or SW swell that pushes through with lighter winds—but these are fleeting. Overall, this is the time to explore other spots or rethink your travel plans.

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Conditions at Nalvo in September

September: Swell Taper, More North Energy

September marks the transition away from the Southwest Monsoon. Average swell height drops slightly to 0.9m, period holds at 7.1s, and ideal wind frequency improves to 28%. The swell distribution begins to shift: SW drops to 22.4%, WSW to 22.3%, but now N (7.9%), NNE (6.3%), and NNW (14.1%) reappear more significantly. The optimal west-southwest energies are still present but decreasing. The wind becomes a little more variable: while SSW (16.8%) and S (14.4%) are still dominant, there are increased contributions from the east and southeast (E, ESE, SE) at over 5% each, offering more chances for offshore flow. The ideal wind percentage rises because of these easterly components. Surf quality improves on average, with more clean mornings and a mix of westerly swell and building north pulses. September can produce some surprisingly good sessions as the monsoon weakens.

Average Spot conditions at Nalvo 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 Nalvo 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 Nalvo for your next trip in September.

Ground swell

Ground swell by size

Wind conditions

Evaluate the wind and swell alignment at Nalvo 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 Nalvo.

Swell with good wind

Swell with good wind by size