January is the middle of the northern Spanish season. The North Atlantic lows are lined up, the swell arrives from the north-west, and the estuary at Mundaka is doing what nothing else in Europe does: peeling a long left along a sandbar a river built.
The month is also a lesson in reading a forecast rather than a calendar. January at Mundaka gives roughly eleven clean days out of thirty, thirteen blown out and seven too small, so half the month is unusable and you do not know which half until four days out. A week booked in January is a bet; two weeks is a plan.
The water is at 13°C and the wave is the hardest and busiest in Spain. Everything that makes it famous, the length, the speed, the sandbar, also makes it unforgiving at a river mouth on an outgoing tide.
