Walnut Creek could see showers Wednesday, Oct. 21, with rain becoming more likely Thursday before sunnier weather returns for the weekend.

The National Weather Service forecast, updated at 1:57 p.m. Wednesday, gives the city a 30% chance of showers after 5 p.m., with a high near 72.

The chance rises to 50% Wednesday night, when less than a tenth of an inch of rain is possible.

Thursday’s forecast calls for a 70% chance of showers, mainly between noon and 4 p.m., with a high near 69. Rainfall could total a tenth to a quarter inch.

Friday should bring patchy morning fog followed by mostly sunny skies and a high near 73. Forecast highs rise to 75 Saturday and 76 Sunday.

“We’re just at the start of our wet season,” National Weather Service meteorologist Cynthia Palmer told KQED in its Oct. 20 report.

Sandbag information

Walnut Creek’s flood-preparedness webpage lists five seasonal sandbag stations:

  • Lancaster Road near Orchard Lane.
  • Heather Farm Park’s ballfields 5 and 6 parking lot, next to the dog park.
  • Larkey Park parking lot.
  • Howe Homestead Park parking lot.
  • Rudgear Park parking lot.

The city says sand and bags are provided for residents and local businesses, but visitors must bring shovels.

The page’s opening notice is dated October 2025. Residents should confirm current station availability with the city’s corporation yard at 925-943-5854.

Contra Costa County’s sandbag information page lists Howe Homestead, 2950 Walnut Blvd., as accessible around the clock. The county program serves residents of unincorporated areas and directs people within city boundaries to their city for distribution information.

Winter preparations

The short-term rain forecast comes as California prepares for possible El Niño-related winter hazards.

In its Oct. 8 outlook, NOAA said strong to very strong El Niño conditions are likely through January–March 2027. El Niño’s strength does not guarantee particular local weather conditions.

Gov. Gavin Newsom declared a state of emergency Sept. 21 to support preparations for potential storms and flooding.

An Oct. 20 Department of Water Resources statement, published by Contra Costa News, said flood-response materials had been positioned at 68 locations statewide, including 4.4 million sandbags and 400,000 tons of rock.

Palmer encouraged residents to clear gutters, replace windshield wipers and watch for slippery roads, KQED reported.