Los Angeles County experienced its wettest Christmas in modern history last week as a powerful "Pineapple Express" atmospheric river dumped extreme rainfall across the region from Dec. 22-29, shattering decades-old records and prompting emergency declarations.
Downtown Los Angeles recorded roughly 4 inches of rain from Christmas Eve through Dec. 26 — the city's second-wettest Dec. 24-26 period on record, surpassed only by 1889. Santa Monica received about 3.1 inches over three days at SMO, while our SMDP rain gauge in NOMA measured 4.8”. Mountain locations saw far higher totals. Mount Wilson in the San Gabriel Mountains recorded over 8 inches during the five-day storm window, and some mountain areas received nearly 18 inches for the week.
Los Angeles International Airport logged 1.88 inches on Christmas Eve, breaking a 1971 record, while Burbank Airport saw 3.42 inches, also a new daily high. Santa Barbara Airport measured 5.91 inches on Christmas Day — its wettest Christmas on record. Meteorologists ranked the event among the top five to 10 wettest starts to Southern California's winter rainy season.
The torrential rains caused widespread flooding and mudslides across the county. Major freeways, including Interstate 5 in Sun Valley, were shut down as lanes flooded. Street intersections from Eagle Rock to South Los Angeles saw deep standing water that stalled vehicles.
The Los Angeles Fire Department conducted at least three swift-water rescues by Christmas Eve, including one dramatic incident in which firefighters rescued a woman carried nine miles down San Jose Creek by raging storm runoff. Officials urged residents to stay off roads as crews responded to flooded streets, downed power lines and debris flows.
Hillside communities faced severe mudslide threats. The mountain town of Wrightwood experienced torrents of mud surging through homes, trapping cars and residents. San Bernardino County fire officials ordered residents to shelter in place due to impassable, mud-covered roads. Mandatory evacuation orders were issued for burn scar areas in the Santa Monica Mountains, including Pacific Palisades and Malibu.
Los Angeles Mayor Karen Bass declared a local state of emergency, while Gov. Gavin Newsom issued an emergency proclamation to mobilize resources. As of Christmas Day, city agencies had responded to over 350 traffic collisions and 600-plus calls about downed trees. Approximately 4,000 Los Angeles Department of Water and Power customers lost power at the storm's peak, though crews restored service to all but two traffic signals by Christmas night.
In a rare occurrence, a small EF-0 tornado with 80 mph winds touched down in Boyle Heights on Christmas morning, damaging roofs and a strip mall. The multi-day storm system was blamed for at least four deaths statewide, though Los Angeles County reported no direct fatalities.
Caltrans reopened a 3.6-mile stretch of Topanga Canyon Boulevard between Pacific Coast Highway and Grand View Drive at noon Saturday after crews removed rockfall and debris. The highway had been closed preemptively on Dec. 23. The corridor remains an active work zone for Palisades Fire recovery efforts and is closed to the public from midnight to 5 a.m. daily.
Health officials issued ocean water quality warnings for all county beaches. The Los Angeles County Department of Public Health advised beachgoers to avoid all water contact, especially near storm drains, creeks and rivers, due to potentially elevated bacteria levels from storm runoff carrying contaminants, debris and trash.