Tropical Storm Hilary inundated desert towns in Southern California on Sunday, breaking records in Palm Springs and other nearby areas with rainfall and flash floods. Video and images showed mudflows and rescues as residents grappled with the unprecedented deluge.

The first tropical storm to hit Southern California in 84 years, Hilary dropped more than half an average year's worth of rain on some areas, including Palm Springs, which saw nearly 3.18 inches of rain by Sunday evening. According to the National Weather Service, the previous record in Palm Springs was 2.03 inches of rain nearly a century ago — on Aug. 1, 1930.

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Considerable flooding, mudflows and road closures created an unfamiliar situation for many residents of the normally arid climate, CBS Los Angeles reported. Interstate 10 was closed in both directions outside of the city and many roads surrounding the area are also impassable, CBS affiliate KESQ-TV reported.

The California Highway Patrol posted images on social media of partially submerged vehicles stuck in the flooding.

The Palm Springs Fire Department posted video on social media of debris floating through floodwaters and said a local emergency had been declared.

"Due to unprecedented rainfall and flooding of local roadways and at least one swift water rescue, Palm Springs City Manager Scott C. Stiles has declared a local emergency due to the critically dangerous impacts of Hurricane Hilary," the department wrote on Instagram.

The Palm Springs Police Department said in a statement Sunday that 911 lines were down and that in the event of an emergency to text 911 or reach out to the nearest police or fire station.

911 lines were also down in Cathedral City and Indio, KESQ-TV reported, and there was no timetable for the lines to return, officials said.

Widespread power outages were reported by Southern California Edison in the area and schools were closed Monday.

Authorities said approximately 50 mobile homes were flooded in Cathedral City and the city posted images of firefighters rescuing four people and one dog from the area.

The National Hurricane Center in Miami downgraded Hilary to a post-tropical storm in its early Monday advisory and warned that "continued life-threatening and locally catastrophic flooding" was expected over portions of the southwestern U.S. on Monday. All coastal warnings were discontinued.

Forecasters warned of dangerous flash floods across Los Angeles and Ventura Counties, and fire officials rescued 13 people from knee-deep water in a homeless encampment along the rising San Diego River. Meanwhile, rain and debris washed out some roadways and people left their cars stranded in standing water. Crews pumped floodwaters out of the emergency room at Eisenhower Medical Center in Rancho Mirage.

Sunday was the wettest day on record in San Diego, with 1.82 inches, the National Weather Service said. The previous record was on Aug. 17, 1977, when 1.8 inches post-Hurricane Doreen dumped record rainfall on the area.

In:
• Hurricane Hilary
• Palm Springs