Weather
Humboldt County, CA Weather: Dense Fog Returns Oct. 21-22
EUREKA, CA – Drivers across Eureka and surrounding Humboldt County communities could encounter dense fog Thursday morning, October 22, as reduced visibility becomes the primary weather concern along C
By Avery Collins · 2026-10-21T11:24:30.704Z
EUREKA, CA – Drivers across Eureka and surrounding Humboldt County communities could encounter dense fog Thursday morning, October 22, as reduced visibility becomes the primary weather concern along California's North Coast. A chance of rain is also expected before conditions improve heading into the weekend.
According to the National Weather Service in Eureka, patchy dense fog is expected after 11 p.m. Wednesday, continuing into Thursday morning. A 30% chance of rain develops Thursday, mainly before 11 a.m., with afternoon temperatures reaching approximately 56 degrees.
The forecast presents a potential travel concern for motorists navigating Eureka, Arcata and surrounding Humboldt Bay communities, where fog can make intersections, pedestrians and approaching vehicles more difficult to see.
Although a broader Pacific weather system is bringing unsettled conditions to portions of California and the Southwest, the local Eureka forecast does not indicate the same significant flash flooding threat highlighted farther south.
Instead, fog, cooler temperatures and a limited chance of rainfall are the principal concerns through Thursday.
Five Day Eureka Weather Outlook Wednesday 10/21: Patchy fog is expected between 8 a.m. and 11 a.m., followed by mostly cloudy conditions. Afternoon temperatures reach approximately 61 degrees, with calm winds becoming westerly around 5 mph. Patchy dense fog develops after 11 p.m., with overnight temperatures dropping to approximately 50 degrees.
Thursday 10/22: A 30% chance of rain is expected, mainly before 11 a.m., with patchy dense fog lingering before 8 a.m. Cloudy skies continue through much of the day, with highs near 56 degrees. North northwest winds increase to approximately 5 to 7 mph during the afternoon. Thursday night becomes partly cloudy, with lows near 45 degrees.
Friday 10/23: Mostly sunny skies return, although temperatures remain cool, reaching approximately 56 degrees. North northwest winds of 6 to 14 mph are expected, with gusts potentially reaching 21 mph. Friday night brings partly cloudy skies and lows near 42 degrees, with occasional gusts as high as 20 mph.
Saturday 10/24: Mostly sunny conditions continue across Eureka, with afternoon temperatures reaching approximately 59 degrees. The forecast does not indicate a significant rainfall threat during the day. Saturday night becomes mostly cloudy, with temperatures falling to approximately 45 degrees.
Sunday 10/25: Partly sunny skies are expected, with afternoon highs near 60 degrees. Sunday night becomes mostly cloudy, with lows around 45 degrees. The relatively quiet weekend pattern follows Thursday's fog and limited rainfall chances.
Morning Visibility Remains the Main Concern Drivers traveling along U.S. Highway 101 through the Eureka and Arcata corridor should remain attentive to changing visibility Thursday morning.
Dense fog can develop unevenly, meaning visibility may deteriorate quickly in some locations while nearby areas remain clearer.
Motorists should use low beam headlights, reduce speeds when visibility is limited and allow additional following distance.
Extended Outlook: October 28 November 3 NOAA's Climate Prediction Center favors above normal precipitation across much of California, including the North Coast, during the October 28 November 3 outlook period.
Temperatures across coastal Northern California are generally favored to remain near seasonal averages.
The outlook reflects broader precipitation and temperature probabilities rather than a forecast of specific storm dates or rainfall totals.
Residents should monitor updated National Weather Service forecasts as Thursday's fog develops and the weekend approaches.