Katagai seasonal overview
Best Surf Season (November - February)
The heart of winter is when Katagai truly fires. From November through February, the Siberian High expands over the Asian continent and pumps sustained offshore winds - primarily from the NW and NNW - across the coast. At the same time, the North Pacific storm track ramps up, sending consistent pulses of ENE and E swell into the ESE-facing beach. The result is the best combination of size, period and grooming wind of the entire year, with offshore flow reaching 48 percent in December and 46 percent in January. Expect average surf in the 4ft (1.2m) range, with larger pulses when the storm track dips south of Japan. These are the months to book your trip.
Fair Surf Season (March - April & September - October)
March, April, September and October are transitional months that mix the energy of winter with the instability of changing seasons. The swell window remains excellent, and average heights actually sneak up to 1.3-1.4m (4-5ft) as early or late-season low-pressure systems pass by. However, wind consistency is lower than mid-winter - only around 20-29 percent offshore - so you will need to chase the windows. On the bright side, water temperatures are still relatively workable, making dawn patrols manageable with a spring or fall wetsuit setup.
Low Surf Season (May - August)
From May through August, Katagai slips into a summer pattern dominated by short-period, locally generated windswell from the ESE and SSE, while the monsoon drives persistent SSW/SW winds and afternoon sea breezes. Offshore flow falls to the 21-25 percent range, and the average period drops to around 8.0-8.4s, with most days offering soft, lumpy conditions. Typhoon season begins to ramp up in August, which can bring bigger, longer-period swell, but it often comes with onshore winds that shred the quality. Unless you are chasing a specific tropical system at a protected bank, this is the quiet season for surf at Katagai.