Trinidad's northern California coast climate is cooler and foggier than visitors from the south sometimes expect. Summer (June–August) is warm but frequently foggy, especially in the morning. The fog burns off by midday on most days, revealing clear afternoons that are ideal for tidepool exploration and hiking. Temperatures in summer rarely exceed 18°C at the coast.
September and October are the most reliably clear months, with lower fog frequency, calm seas, and the tail end of summer warmth. This is the best time to visit if you want good weather for outdoor activities.
Winter is wet, cool, and stormy, but the stormy conditions produce the most dramatic surf and seabird activity. Grey whale migration begins in December, and humpback whales feed offshore from July through November. The Dungeness crab season opens in November–December, making fresh crab available from the harbour.
Spring (April–May) is migration season for shorebirds and seabirds, and the wildflowers on the headland trails are at their best. Grey whales move north through the area in March and April, often close enough to be seen from the headland without binoculars.