Dagupan is not a sightseeing town in the conventional sense — the sights are the markets, the fish farms, the river, and the food. A half-day on foot covers the cathedral area, the Magsaysay Market, and a walk along the river; an afternoon on a banca into the surrounding fishponds gives the better sense of why this place matters.
The big event is the Bangus Festival in April. The rest of the year, time your visits to align with the morning fish auctions (around five to seven am) at the river markets.