Subic Bay sits in the rain shadow of the Zambales Mountains, which gives it a somewhat drier climate than Manila, though it still follows the Philippine wet/dry pattern. The dry season runs from November through April — this is the best time to visit, with low humidity, good visibility for diving, and reliable beach weather. January and February are the coolest months, when daytime temperatures settle in the mid-20s.
The wet season from June through October brings afternoon downpours and occasional typhoons, though the mountains provide some shelter from storms tracking across the central Philippines. Visibility in the bay drops during heavy rain but wreck diving remains possible when weather permits. The jungle is greenest and most atmospheric after the rains.
Christmas and Easter (Holy Week) are the busiest periods — Manila empties out and Subic fills up. Hotels charge peak rates and the weekend crowds at Ocean Adventure and Zoobic Safari can be overwhelming. Unless you enjoy company, avoid these periods or book well ahead.
The Subic International Film Festival runs annually in June; the Triboa Bay Mardi Gras, a festival of music and food held in February, draws large Manila crowds for its weekend run.