EUREKA, Calif. – Northern California’s first week of fall is bringing a noticeable shift, with clouds, cooler nights, and patchy morning fog likely by Thursday, September 25. Drivers on U.S. Highway 101 should plan for reduced visibility and slower travel during early commutes.
According to the National Weather Service office in Eureka, Tuesday remains sunny with a high near 67. By Thursday, conditions turn partly cloudy with highs near 63 and breezy northwest winds around 10 mph. These changes mark the first hint of seasonal cooling across Humboldt County as the region transitions into fall.
Eureka and Arcata will see nighttime lows dropping into the lower 50s by Thursday night. Coastal residents should be prepared for heavier jackets and slower morning starts due to marine layer clouds and fog. In inland areas such as Fortuna, temperatures will trend cooler as well, signaling an early seasonal pattern shift.
Travelers on U.S. Highway 101, particularly along stretches near Humboldt Bay, should watch for fog-related hazards during the morning hours this week. Reduced visibility may create dangerous conditions for commuters and commercial drivers. The National Weather Service recommends allowing extra travel time and keeping headlights on low beam in fog.
While the cooler pattern dominates through Thursday, no rain is expected until late in the weekend. Sunday night into Monday could bring the season’s first chance of showers, with highs holding in the 60s and lows in the low 50s.
Residents should monitor updates as fall continues to settle in across Northern California, with more rain chances expected early next week.
Five Day Forecast for Eureka, CA
- Tuesday: Sunny, high 67, low 56
- Wednesday: Mostly sunny, high 67, low 55
- Thursday: Partly sunny, high 63, low 52
- Friday: Mostly sunny, high 65, low 53
- Saturday: Mostly sunny, high 64, low 53
