Trinidad's climate is completely dominated by the breathtaking power of the Pacific Ocean. While there are definite rainy and dry seasons, Trinidad rarely goes more than a few days without the sun breaking through for a few hours. The rainy season lasts from November through April accounting for about 90 percent of the annual precipitation, averaging about 40 inches.
This dramatic weather pattern brings an early Spring explosion of some of the most diverse wildflowers you are likely to find anywhere. The dry season, lasting from May through early November, is typically marked by low clouds and fog which usually clear by late morning. Early mornings in "summer" can be so calm that the Bay looks like a lake more than an ocean - good time for salmon fishing. Early afternoon is generally sunny with the low clouds moving back in by evening. Fall weather is absolute paradise - still sunny days, warm temperatures, and calm seas. When the winter storms hit the Trinidad Coast, people line the headlands to watch. The winter swells travel hundreds of miles from the Gulf of Alaska, and often reach 25 to 30 feet in height! Seeing " a perfect 10 over Pilot (rock) is an unbelievably exciting event here.
Temperatures are quite moderate, and the annual range is one of the smallest in the lower 48 states. The record high in nearby Eureka is only 85°(F) while the record low is 20°(F). During a typical year, the coldest lows are in the mid 30s and the warmest highs occasionally reach the mid 80s.
The Pacific Ocean's cold and often unexpected upswells, along with chilling blasts or blankets of fog can change the weather in an instant. In "summer", while we're enjoying our natural "air-conditioning", and appreciating the fog nurturing the Redwoods, inland communities have huge ranges in temperature. Areas just over the coastal mountains, about 40 miles east of Trinidad, can experience summer highs above 110 degrees, and winter lows in the teens! Driving east on 299, you can watch the temperature go up a degree per mile.
Layers, layers, layers. Trinidad visitors should always grab a light jacket. While the locals whip out their shorts and surfboards and hit the beaches even in February, many tourists aren't accustomed to the rapid weather changes that can occur over the course of a day.