Over 40 earthquakes were recorded along the Calaveras fault southeast of San Ramon, California, between November 9 and 10, 2025. The largest event, M3.8, occurred at 09:38 LT (17:38 UTC) on November 9 at a depth of 9.2 km (5.7 miles). Geological and seismic studies show that the Calaveras fault is capable of generating an event in the M6.5 to M7.0 range over long-term timescales.
A developing low-pressure system over the Northeast Pacific is forecast to direct a strong atmospheric river (AR) toward California between November 12 and 15, 2025. The Center for Western Weather and Water Extremes (CW3E) indicates a high probability of moderate to strong AR conditions in Northern and Central California, with heavy precipitation possible in the Sierra Nevada and coastal ranges.
Four back-to-back atmospheric rivers are forecast to make landfall along the U.S. West Coast between November 3 and November 9, 2025. Heavy rainfall totals of 76–130 mm (3–5 inches), with isolated amounts up to 177 mm (7 inches), could lead to localized flooding in parts of northern California and Washington State throughout the week.
A Heat Advisory is in effect for parts of southern California from Tuesday morning through Wednesday evening, October 28 to 29, 2025.
Two atmospheric rivers are forecast to hit the Pacific Northwest and northern California, starting late Thursday, October 23, 2025. The systems are forecast to bring in heavy rainfall of over 130 mm (5 inches) along with mountain snow across Washington, Oregon, and northern California.
Tornado warnings were issued across parts of Central California, including San Luis Obispo County, as a rare October storm brought heavy rainfall, gusts exceeding 110 km/h (70 mph), and localized flooding on October 13–14, 2025. Evacuation warnings were declared in Los Angeles County for burn-scar areas at risk of debris flows, while forecasters maintained a marginal tornado risk for southern coastal regions.
A Pacific storm will move into California from the northwest between October 13 and 15, 2025, bringing widespread valley rain and heavy snow to the Sierra Nevada. Snowfall totals along the Sierra crest may reach 30–90 cm (12–36 inches), with hazardous driving conditions expected across Interstate 80 and other major passes. The National Weather Service warns that chain controls and travel delays are likely during the peak of the event.
A predecessor rain event (PRE) associated with Hurricane Priscilla is forecast to produce sustained rainfall across the Southwestern United States, particularly Arizona and New Mexico, between October 9 and 11, 2025.
A section of coastal bluff measuring about 91–122 m (300–400 feet) collapsed in Rancho Palos Verdes, California, on September 28, 2025, falling 15–18 m (50–60 feet) toward the ocean. Four backyards were damaged, but no homes sustained structural damage, and no injuries were reported. Authorities said the collapse occurred outside the long-active Portuguese Bend Landslide Complex, located about 6 km (4 miles) away.
A series of atmospheric rivers (AR) is forecast to hit the U.S. West Coast from late September through early October, beginning with a strong AR that made landfall over British Columbia on September 26, 2025. Forecasts show moderate AR conditions in Washington, Oregon, and northern California on September 28, followed by a stronger system making landfall on September 30 and potentially continuing into October 7.
