Eureka, CA – Winter has settled in across northwest California over the past few nights, bringing repeated rounds of near-freezing temperatures to interior valleys. Cold conditions are expected again tonight, especially across Trinity County, northeast Mendocino County, and interior Humboldt. Lows are forecast to fall back into the mid-30s, with areas of frost possible.
According to the National Weather Service in Eureka, a light onshore wind early Sunday may help keep coastal temperatures a bit milder. However, the interior will continue to experience cold overnight lows, with frost forming in patches—particularly in sheltered valleys where fog is minimal.
Valley fog is expected to remain an issue tonight and early Sunday, which may limit frost in some locations while enhancing it in others. Forecast charts show widespread interior lows between 33–36 degrees, enough for sensitive plants, gardens, and outdoor pets to be impacted.
The NWS advises residents to protect vulnerable vegetation and ensure adequate shelter for pets, especially in areas where temperatures may briefly dip to freezing or just below. With the colder nights persisting through the weekend, repeated frost remains possible.
The cold pattern is expected to gradually ease later in the week, though interior valleys may still see chilly mornings before conditions warm.
