Weather
Humboldt County, CA Weather: Fog Returns Sunday, Oct 18
Eureka, CA – A noticeable shift toward cooler, cloudier weather is expected along Northern California's Humboldt County coastline this weekend, with afternoon temperatures gradually falling from 68 de
By Lauren Beckett · 2026-10-15T10:06:19.339Z
Eureka, CA – A noticeable shift toward cooler, cloudier weather is expected along Northern California's Humboldt County coastline this weekend, with afternoon temperatures gradually falling from 68 degrees Thursday to the mid 50s by early next week. Sunshine will give way to increasing clouds Saturday, followed by patchy coastal fog Sunday morning and a chance of rain Monday. The changing conditions could affect morning visibility, outdoor activities and travel along U.S. Highway 101 as Eureka transitions into a cooler mid October weather pattern.
According to the National Weather Service in Eureka, temperatures are expected to reach approximately 68 degrees Thursday, Oct. 15, before dropping to 62 Friday and 59 Saturday. The cooling trend continues Sunday, Oct. 18, when the afternoon high is expected to reach only 57 degrees. By Monday, Oct. 19, temperatures could fall to approximately 55 degrees, representing a 13 degree decline from Thursday's projected high.
Weekend Brings Cooler Temperatures and Increasing Clouds Thursday will offer the warmest conditions of the forecast period, with sunny skies and light, variable winds across Eureka. Temperatures are expected to reach 68 degrees before falling to around 50 Thursday night. Friday brings partly sunny skies and a high near 62 degrees, with calm winds becoming north northwesterly around 5 mph during the afternoon.
By Saturday, the weather becomes noticeably cooler and cloudier. Mostly cloudy skies are expected, with afternoon temperatures reaching approximately 59 degrees. North northwest winds of 5 to 8 mph may develop during the afternoon, while nighttime temperatures settle near 49 degrees.
Sunday brings another change as patchy fog develops before 11 a.m., potentially reducing visibility in portions of the coastal area. The National Weather Service expects mostly cloudy skies afterward, with temperatures reaching around 57 degrees.
Coastal Travel and Outdoor Conditions The combination of cooler temperatures, increased cloud cover and possible morning fog could affect residents traveling through Eureka, Arcata and surrounding Humboldt Bay communities. Drivers using U.S. Highway 101, particularly near coastal lowlands and areas prone to fog, should be prepared for localized reductions in visibility Sunday morning.
Although the forecast identifies patchy fog, it does not indicate a dense fog advisory or widespread hazardous driving conditions. Motorists should use appropriate headlights and adjust speeds if visibility becomes limited.
Outdoor activities along the Humboldt Bay waterfront, nearby beaches and coastal recreation areas may also feel considerably cooler than Thursday's sunny conditions. Residents planning weekend outings should consider bringing additional layers, especially during the morning and evening hours.
Rain Chances Return Early Next Week The next notable weather development arrives Monday, when the National Weather Service forecasts a chance of rain after 11 a.m. Mostly cloudy skies are expected, with temperatures reaching approximately 55 degrees.
A slight chance of rain continues Monday night as temperatures fall to around 44 degrees. The supplied forecast does not provide rainfall totals or precipitation probabilities, leaving uncertainty about how widespread or substantial any showers may become.
Conditions should begin improving Tuesday, with mostly sunny skies and a high near 57 degrees. Wednesday brings another mostly sunny afternoon, with temperatures reaching approximately 59 degrees.
With cooler temperatures, patchy fog and the possibility of rain approaching, will the changing coastal weather affect your weekend plans?
Five Day Weather Outlook Thursday 10/15: Sunny skies will bring afternoon temperatures near 68 degrees across Eureka, making Thursday the warmest day of the supplied forecast. Light and variable winds are expected, followed by partly cloudy conditions and a nighttime low around 50.
Friday 10/16: Partly sunny skies are expected as temperatures cool to approximately 62 degrees. Calm winds become north northwesterly around 5 mph during the afternoon, with mostly cloudy conditions developing Friday night and temperatures falling to around 48.
Saturday 10/17: Mostly cloudy skies will dominate the day, with afternoon temperatures reaching approximately 59 degrees. North northwest winds of 5 to 8 mph are expected during the afternoon, followed by mostly cloudy conditions and a nighttime low near 49.
Sunday 10/18: Patchy fog is possible before 11 a.m., followed by mostly cloudy skies and an afternoon high near 57 degrees. Drivers should watch for localized visibility reductions, with nighttime temperatures expected to fall to approximately 45.
Monday 10/19: Mostly cloudy skies and a chance of rain after 11 a.m. will accompany cooler temperatures near 55 degrees. A slight chance of rain continues Monday night, with temperatures dropping to approximately 44 degrees.
Extended Outlook Tuesday, Oct. 20, is expected to bring partly sunny skies and temperatures near 57 degrees, followed by partly cloudy conditions and a low around 46 Tuesday night.
Wednesday, Oct. 21, should remain mostly sunny, with temperatures reaching approximately 59 degrees. No additional significant storms or hazardous weather conditions are identified in the supplied forecast through Wednesday.