Isla Grande seasonal overview
Best Surf Season (May - October)
Summer brings the sweet spot for Isla Grande. While average swell heights drop to a modest 0.8-1.4m, the trade winds weaken dramatically and become more variable. The percentage of time with ideal offshore wind from the SW, WSW, or W jumps to 25-42%, compared to just 1% in winter. This means that the consistent NE background swell (which still dominates over 70% of the time) can actually be surfable. Expect fun-sized waves in the 1-1.5m range with clean faces and occasional punch from longer period pulses associated with tropical waves. The key is waiting for the afternoon sea breeze to swing offshore or a passing trough to bring light southerly flow. This is the window for the best surf quality at Isla Grande.
Fair Surf Season (April & November)
These transitional months offer a mix of winter's power and summer's finesse. April sees the tail end of the strong NE trades, with average swell still at 1.3m but ideal wind only 5% – a rare treat when it aligns. November benefits from the retreat of the trades, with ideal wind 28% and swell rebuilding toward winter levels (1.1m average). Both months can deliver pumping surf if a cold front pushes through the region, flipping winds to the offshore quadrant. However, consistency is low; be prepared to wait out the prevalent onshore flow.
Low Surf Season (December - March)
The winter months are the heart of the dry season, dominated by the relentless NE trade winds. The Azores-Bermuda High strengthens, channeling strong winds from the NNE through ENE across the Caribbean. This creates the largest average surf of the year (1.6-1.8m) with robust 8-second periods, but the wind is almost always onshore – blowing from the same direction as the swell. Only 1-7% of the time does the wind swing to an offshore direction (SSW-W). When that rare combo happens, you get overhead, powerful waves at Isla Grande. But for the most part, expect choppy, blown-out conditions. This season is best for those seeking size and are willing to battle the wind, or for experienced chargers on big wave craft.
Loading chart...
Conditions at Isla Grande in December
December: Winter Roars Back
December sees a dramatic increase in swell: average 1.7m, period 8.0s. NE swell dominates at 80.9%, with a significant 31.7% in the 1.5-2m range and 16.6% in 2-2.5m. The trade winds are back in force: NNE and NE winds combine for 68% of the time, with many observations in the 20-30kph range. Ideal offshore wind plummets to 7%. The surf is powerful and consistent but largely blown out. There are brief windows when a cold front can swing the wind to the west or northwest, which can produce exceptionally good waves. Overall, December is for the hardcore – big surf, strong wind, and only occasional clean moments. It's a month of potential rather than reliability.
Average Spot conditions at Isla Grande in December
Swell history for December
Wind history for December
Swell quality
Analyze the groundswell consistency at Isla Grande 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 Isla Grande for your next trip in December.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Isla Grande 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 Isla Grande.
