Powerful storm drenches SLO County. Here’s how much rain fell and what’s next
The first sizable storm of the season swept across San Luis Obispo County on Monday night, complete with thunderstorms that prompted a flurry of alarming alerts and dumped more than 2 inches of rain at some locations across the Central Coast.
The National Weather Service issued a severe thunderstorm warning, a flash flood warning and even a tornado warning late Monday night.
Luckily, it didn’t appear that a tornado touched down during the storm, but emergency alerts advised people to get inside, take cover and potentially shelter in a basement or interior room.
At the height of the storm, a line of thunderstorms was recorded around 11:11 p.m. extending from 11 miles east of Cambria to 10 miles southwest of Morro Bay, the Weather Service said, directing a firehose of precipitation across the county.
“You rarely see a National Weather Service map look like this for the Central Coast,” meteorologist John Lindsey wrote on X on Monday evening. “Tonight’s cold front is delivering exceptionally intense rainfall across the Central Coast.”
The heavy rainfall send rocks and dirt tumbling down onto Highway 41 between Morro Bay and Atascadero, making for a harrowing drive.
“Cops, tow trucks and debris everywhere,” one Facebook user posted witih a video showing the roadway littered with rocks that had fallen from the slope nearby.
“I don’t even know how to get through this,” she exclaimed on the video, before navigating her car to the shoulder and around the obstacles.
Also Monday evening, a power outage cut off electricity to 3,403 San Luis Obispo County PG&E customers as the storm began to strengthen.
According to PG&E’s outage report map, customers in the Los Osos Valley Road area between San Luis Obispo and Los Osos lost power around 6:22 p.m.
By Tuesday morning, SLO County locations had received anywhere from 1.04 inches to more than 2 inches of rain in the 24-hour period ending at 9:27 a.m., according to the San Luis Obispo County Public Works Department.
Rocky Butte, a location in the mountains northeast of Cambria, led the way with 2.52 inches of rainfall, while Atascadero was not far behind at 2.36.
The San Luis Obispo area received about 1.65 inches of rain, while the South County topped out at around 1.65 inches in eastern Nipomo.
The North County ranged between 1.39 inches in Templeton, Creston and Hog Canyon to 1.99 inches at the Salinas Dam at Santa Margarita Lake.
Here’s a look at all the totals from across the county, according to SLO County Public Works and the National Weather Service:
- Arroyo Grande: 1.54 inches
- Atascadero: 2.36 inches
- Cambria: 1.41 inches
- Camp San Luis Obispo: 1.54 inches
- Canet near Morro Bay: 1.81 inches
- Creston: 1.39 inches
- Davis Peak (near Montaña de Oro): 1.42 inches
- Hog Canyon (north of Paso Robles): 1.39 inches
- Highway 46 West: 1.77 inches
- Las Tablas: 1.72
- Lopez Dam: 1.59 inches
- Los Berros: 1.54 inches
- Los Osos: 1.62 inches
- Morro Toro (Highway 41): 2.36 inches
- Nipomo East: 1.65 inches
- Nipomo South: 1.35 inches
- Oceano: 1.2 inches
- Rocky Butte: 2.52 inches
- Salinas Dam: 1.99 inches
- San Simeon: 1.14 inches
- Santa Margarita: 2.15 inches
- San Luis Obispo: 1.65 inches
- San Luis Obispo at Cal Poly: 1.44 inches
- SLO Reservoir: 1.62 inches
- Shandon: 1.24 inches
- South Portal (Cuesta Grade): 1.64 inches
- Paso Robles: 1.31 inches
- Nacimiento River (county line): 1.37 inches
- Templeton: 1.39 inches
- Upper Lopez: 1.34 inches
- La Panza: 1.04 inches
- Bald Mountain: 1.85 inches
- Branch Mountain: 1.39 inches
What’s ahead in SLO County’s forecast
San Luis Obispo was in for a 90% chance of rain on Tuesday, with the potential for thunderstorms and up to a quarter inch of rain, the Weather Service said.
Meanwhile, Paso Robles had an 80% chance of rain on Tuesday, with the potential for 20 mph wind gusts, thunderstorms and less than a tenth of an inch of rain, the Weather Service said.
The Weather Service said Morro Bay had a 90% chance of rain on Tuesday, with the potential for thunderstorms.
The storm should ease by the evening, with partly cloudy skies forecast for Tuesday night in San Luis Obispo, Paso Robles and Morro Bay.
By Wednesday, the sun was expected to break through the clouds across the county.
San Luis Obispo, Paso Robles and Morro Bay were forecast to enjoy partly cloudy skies for the rest of the week.
Avoid ocean water contact after storm
Meanwhile, the county Public Health Department sent out an advisory Tuesday urging people to avoid ocean water contact for at least three days after significant rainstorm like the one that occurred this week.
“Rainstorm runoff is known to transport high levels of disease-causing organisms such as bacteria, viruses and protozoa from the watershed and urban areas to the ocean,” the county said in its news release, noting that the organisms can cause skin, respiratory, and intestinal problems, particularly in young children, older adults, and people with compromised immune systems.
“Surfers, swimmers and others are advised to avoid contact with ocean water during this period, especially in areas close to creeks, rivers, storm drains and other runoff outlets that empty into the ocean,” the county said.
For more information about beach water quality, visit the Public Health Department Beach Water Quality website at www.SurfSafeSLO.org, or call the Ocean Water Monitoring Program Telephone Hotline at 805-788-3411.
This story was originally published October 14, 2025 at 10:23 AM with the headline "Powerful storm drenches SLO County. Here’s how much rain fell and what’s next."