The best time to visit Vigan is during the dry season, which runs roughly from November to April. January and February are the coolest months and the most comfortable for walking the heritage zone; temperatures in the low to mid twenties Celsius make the cobblestone streets genuinely pleasant rather than exhausting. The Vigan Festival of Arts (Kannawidan Festival) takes place in late January, filling the plazas with cultural performances, street food, and crowds — it is lively but the accommodation books up fast.
From May onwards the heat builds, and June through October is typhoon season in northern Luzon. Typhoons do not always hit Vigan directly, but the region can be wet and occasionally disrupted during these months. The rice harvest season in October and November brings a different kind of beauty to the surrounding Ilocos countryside, and visitor numbers thin out compared to the Christmas holiday peak.
December and the Christmas period are busy — Filipinos travel extensively at Christmas and Vigan, being one of the country's most celebrated heritage destinations, draws visitors from Manila and the rest of Luzon. If you are visiting around this time, book accommodation in advance.