El Mongol seasonal overview
Best Surf Season (October - March)
The North Atlantic delivers its full fury during these months, with powerful extratropical cyclones churning out consistent, long-period swell from the NW to NNW that directly hits El Mongol's north-facing beach. Average wave heights range from 1.4m to 1.8m and periods frequently exceed 11s, often reaching 12-13s. The NAO index often turns negative, steering storm tracks southward and feeding the Bay of Biscay. Offshore winds from the S and SSW blow reliably 48-60% of the time, creating clean, glassy faces. This is the prime window for pumping, firing surf up to 2.5m+ on the best days.
Fair Surf Season (April - May & September)
As the North Atlantic slowly transitions, swell energy drops with average heights around 1.0-1.3m and periods settling into the 9.8-10.6s range. The wind patterns shift: the frequency of ideal offshore winds decreases to 27-33%, and cross-shore or light onshore conditions become more common. Still, late-season storm pulses in September can deliver solid NW swell with punchy, rideable waves when the synoptic setup aligns. Spring months offer fun-sized surf for groveling, but expect less consistency.
Low Surf Season (June - August)
Summer brings the Azores High dominating the eastern Atlantic, suppressing storm activity. Swell becomes small and short-period (0.9m, 8.7-9.0s on average), mostly from decaying NW swell trains. The wind pattern flips: onshore N and NE breezes become prevalent, and offshore winds from the south occur only 16-20% of the time. The result is typically choppy, messy conditions with small, weak waves. Only the occasional lucky window of S winds and a stray long-period swell can salvage a session, but generally this is a time for flat spells and groveling.
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Conditions at El Mongol in December
December: Deep Winter Peak
December is the pinnacle of the surf season at El Mongol. Average swell height is 1.7m with a 12.3s period, and the frequency of ideal offshore winds hits a yearly high of 60%. Swell comes predominantly from the NW (39%), with strong secondary pulses from WNW (15%) and NNW (18%). Southerly winds (S, SSW, SW) combine for over 30% of observations, ensuring clean conditions on many days. This month sees the most consistent combination of size, power, and glassy winds. When the NAO is negative and a deep low parks west of the UK, expect pumping NW swell that can reach 2.5m+ with light S winds – absolutely firing conditions that draw the committed crew.
Average Spot conditions at El Mongol in December
Swell history for December
Wind history for December
Swell quality
Analyze the groundswell consistency at El Mongol 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 El Mongol for your next trip in December.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at El Mongol 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 El Mongol.
