Tywyn seasonal overview
Best Surf Season (November - February)
Tywyn faces west-southwest, which means the best swell directions - SW, WSW, W and WNW - arrive straight from the storm tracks of the North Atlantic. From November through February, those storm tracks are most active: average wave heights sit in the 3-4ft (0.9-1.2m) range in November and February and push toward 3.6ft (1.1m) in December and January, while wave periods hold near 8 seconds or better. Offshore easterly winds from NE, ENE, E and ESE are never common, but they are most frequent in winter, giving Tywyn its highest chance of clean and rideable surf at 11-12 percent of the time. The combination of solid west-northwest to southwest swell and occasional cold, offshore easterly breezes makes this the prime surf window, despite water temperatures bottoming out near 7-9°C.
Fair Surf Season (March - May and September - October)
The shoulder seasons are a game of patience. March still receives the tail end of winter's energy with 3ft (0.9m) average swells and an 8.2s period, but by April and May the Atlantic storm machine begins to shut down, dropping average heights to 2ft (0.6m) and periods into the 7s. September and October represent the flip side: the North Atlantic starts to reawaken, with September's average swell already back to 2.3ft (0.7m) and October climbing to 3ft (0.9m) as autumn lows deepen. Ideal wind conditions hover between 5 and 10 percent in these months, so more sessions will be small or onshore, yet when the wind swings offshore these months can offer clean, punchy surf with milder air and water.
Low Surf Season (June - August)
Summer at Tywyn is the low season in every sense. The Azores High bulges northeastward, pushing the North Atlantic storm track away from the UK and leaving Tywyn with average wave heights of only 1.6-2ft (0.5-0.6m) and short, uninspiring periods of 6.0-6.6s. Onshore flow from SW, WSW, W and WNW dominates much of the summer, and ideal offshore winds drop to a rare 2-3 percent of the time. The water warms to a pleasant 16-18°C and the beaches come alive with summer energy, but serious surfers will need a longboard, a low tide sandbank, and patience.