Iba has a clear dry season (November to May) and a wet season (June to October) shaped by the southwest monsoon. The best time to visit is November through April: the weather is reliably dry, the South China Sea is calm, and the beaches are at their best.
April is the peak of mango season — the famous Dinamulag variety ripens in late April and early May, and prices are low while quality is high. The week-long Paynauen Festival, held in the last week of April, celebrates the mango harvest with street dancing, sand-castle competitions, cultural shows, and outdoor markets. It draws visitors from across Luzon and gives the usually quiet town a genuine festive atmosphere.
May is the tail end of the dry season and still excellent for beach visits, though it can be very hot (30–34°C) with high humidity.
June through October brings the rainy season. Typhoons occasionally make landfall on the Zambales coast, and the South China Sea can be rough. Swimming is possible between rainstorms, but this is not the time to plan a beach trip.
December through February is cool and dry — the most comfortable temperatures of the year, rarely above 28°C, and nights can feel fresh. This is a quieter period without the festival crowds, good for those who just want the beach without the noise.