Lake Arenal, a man-made reservoir near the town of Tilarán, is one of the top windsurfing spots in the Americas. Steady thermal winds of 30 to 45 mph funnel through the gap between the Arenal Volcano and the Tilarán mountains from November through April, making conditions reliable and strong.
The lake is framed by low green ridges and the water stays relatively flat, which suits both intermediate and advanced sailors. Several operators on the western shore rent equipment and offer lessons. The season peaks from December to March, when winds are most consistent.
Beyond the lake, Costa Rica's Pacific coast — particularly spots around Bahía Salinas in Guanacaste — also draws windsurfers looking for ocean swells and open-water conditions.