Puerto Plata's north coast receives rainfall year-round — the Atlantic-facing slopes of the Cordillera Septentrional catch moisture from the trade winds — but the driest and most reliable months are December through April. This period also coincides with peak tourist season, when the resort towns to the east fill up and prices rise accordingly. January and February offer the most consistently clear weather, including for the Teleférico cable car, which closes on rainy days.
The wetter months from May to November are not without their appeal: the city is quieter, prices are lower at local hotels and restaurants, and the surrounding countryside is more intensely green. The Dominican Republic is in the Atlantic hurricane belt, and the peak risk period runs from August through October. Direct hits are relatively rare on the north coast, but tropical weather systems can bring several days of heavy rain. If your main reason for coming is the city's sights rather than beach weather, the shoulder months of May–June and November can offer a reasonable compromise of good conditions and lower prices.
The Puerto Plata Cultural Festival in October brings music, dance, and folkloric events to the city's plazas and is worth timing a visit around if you are in the country at that time.