The week of October 13, 2025, marks a remarkable chapter in California weather. From record-setting rainfall in San Jose to the first severe thunderstorm watch in Los Angeles in nearly two decades, this event highlights the changing risks and unpredictability facing our region.
Unprecedented Rainfall: San Jose and Los Angeles Break Records
For many in the Bay Area, the rain was more than a seasonal nuisance—it was historic. San Jose logged 1.52 inches of rainfall in a single day, making it the second-wettest October day ever observed since records began in 1897. This deluge far surpasses the city’s entire average rainfall for October—delivering three months’ worth of precipitation in less than 24 hours.
Meanwhile, downtown Los Angeles was equally soaked with 1.38 inches of rain, doubling the region’s monthly average in a day and sparking flash flood concerns. In the San Gabriel Mountains, 72-hour rainfall totals eclipsed 4 inches, highlighting the localized intensity these storms can unleash.
A Rare and Historic Severe Thunderstorm Watch for LA
The National Weather Service issued a severe thunderstorm watch for Los Angeles—its first in over 17 years. Such warnings are virtually unheard of in Southern California, where severe weather is most often associated with winter rains and Santa Ana wind events, not classic summertime thunderstorms. The previous watch had occurred back in January 2008, underscoring the rarity and seriousness of this week’s weather.
The watch placed nearly 10 million residents under alert, warning of damaging winds, hail, and even a tornado risk—phenomena many locals had never experienced in their lifetimes.
Why Is This So Significant?
Meteorological records serve as both warning and opportunity—reminding us to invest in better storm monitoring, public awareness campaigns, and infrastructure resilience. This “once-in-a-generation” week makes clear that California’s weather patterns are evolving, and the risks may be intensifying thanks to climate change, urban expansion, and shifting storm tracks.
What to Watch Going Forward
- October rainfall records broken in both Northern and Southern California
- Los Angeles’ first severe thunderstorm watch in 17+ years
- Heightened focus on communicating rare hazards to the public
- Importance of adaptive local weather forecasting and community readiness
As California’s weather demonstrates new extremes, accurate communication and preparedness remain essential.
San Gabriel Mountains: 4.5 inches
San Jose: 1.52 inches
Downtown Los Angeles: 1.38 inches
This visualization highlights how the San Gabriel Mountains saw the highest totals during the event, while both San Jose and Downtown Los Angeles also experienced rare, record-breaking rainfall.