Hilary has triggered flooding, heavy rains and powerful gusts across parts of the western US and Mexico, transforming streets into raging rivers and forcing some residents to flee, and leaving others in need of rescue, even after the storm weakened to a post-tropical cyclone.

More rain was expected to fall throughout Monday and Tuesday as officials cleaned up the aftermath. After hitting Southern California on Sunday as a tropical storm – the state’s first since 1997 – Hilary headed into Nevada as its first-ever recorded tropical storm. As Hilary and its remnants moved up the western US, the storm brought power outages, flooding and calls for residents to evacuate or shelter in place.

Live updates: Hilary brings major flood risk to California

The storm broke rainfall records across Southern California: Palm Springs got nearly a year’s worth of rain with 4.3 inches in 24 hours, one of its rainiest days ever. Death Valley nearly set a record with 1.68 inches, and the Furnace Creek area, which usually gets about two-tenths of an inch in August, got 0.63 inches.

ADVERTISEMENT Advertisement

And the storm is the rainiest tropical storm system in Nevada’s history, nearly doubling the state’s 116-year-old all-time record, according to preliminary data from NOAA’s Weather Prediction Center. Hilary has released 9.20 inches of rain on Lee Canyon, Nevada, smashing the previous record of 4.36 inches in 1906.

Hilary also became the rainiest tropical system in Idaho, Oregon and Montana history.

In Montana, Hilary dropped 2.3 inches of rain, breaking the record for the rainiest tropical system to hit the state set by Kathleen in 1976. In Oregon, 3.29 inches that fell on Morgan Mountain from Hilary broke the old record of 1.35 inches, also from Kathleen.

And the 3 inches of rain that fell on Dollarhide Summit, Idaho, from Hilary broke the record of 2.20 inches set by Olivia in 1982.

Localized flooding was possible into Tuesday morning across northern portions of the Intermountain West.

In Palm Springs, a section of Interstate 10 was shut down for part of Monday while road crews cleared mud left by floodwaters from Tropical Storm Hilary, but other routes in and out of the desert oasis near Joshua Tree National Park were open.

In addition, many freeway off-ramps were limited because of mud, and CalTrans crews are working to clear those in an effort to ease accessibility.

Emergency telephone service, which had been down since midmorning, has been restored, the police department said, but an outage continues to affect other areas of the Coachella Valley.

“We are not used to this level of precipitation, generally – certainly not in the middle of summer,” San Diego Mayor Todd Gloria told CNN on Sunday.

“With what we’re expecting, it may overwhelm us.”

Tropical storm Hilary caused a section of the normally-dry Whitewater River to flood parts of a golf course in Cathedral City, California. (Photo by Mario Tama/Getty Images) - Mario Tama/Getty Images

Here’s the latest:

• Heavy rains and some flooding may continue Tuesday morning in parts of the Intermountain West, according to the National Hurricane Center. The rain will cause “mostly localized areas of flash flooding,” the National Weather Service Prediction Center said. Flood watches remained in place Monday night across seven Western states.

• Strong and gusty winds were expected in Nevada, western Utah, southern Idaho and southwest Montana, the hurricane center said. Coastal tropical storm warnings have been discontinued.

• Some portions of Southern California lost power during the storm but electricity was mostly restored by Monday evening. A total of about 41,000 customers in Los Angeles were without power at one point, Marty Adams, general manager and chief engineer at the Los Angeles Department of Water and Power, said Monday.

• People in parts of Southern California should not travel unless they are fleeing an area under flooding or under an evacuation order, the National Weather Service has warned.

• Flooding, mudslides and downed trees and wires were widely reported across Southern California on Sunday and Monday. At least nine people were rescued Sunday in a San Diego riverbed, San Diego Fire-Rescue said, with water rescues also reported in Ventura County and Palm Springs.

• In Mexico, where the storm first landed, power has been restored to 80% of customers in the three states affected by Hilary, according to the national power company. “379,850 users have been affected, and electricity supply has been restored to 302,134, equivalent to 80%,” said the Federal Electricity Commission in a statement Monday.

Maura Taura surveys the damaged cause by a downed tree outside her home. - Marcio Jose Sanchez/AP

To the west, Los Angeles and Ventura counties saw “considerable damage” Sunday night amid reports of dangerous flash flooding, and rock and mudslides, the National Weather Service said, adding up to half an inch of rain could fall per hour.

Cars were stuck in floodwaters in the Spanish Hills area, the National Weather Service reported.

Crowley urged residents to take precautions on the roads.

“A relatively small amount of water can sweep a vehicle away,” she said.

In Los Angeles, the worst of the storm was over as of Monday morning, according to officials. All weather warnings in the city were canceled. “We are past the brunt of the impact,” said National Weather Service meteorologist Ariel Cohen.

First day of school is a wash for some students

Schools in San Diego and Los Angeles are set to reopen Tuesday after closing Monday in anticipation of the storm. Officials canceled classes for the more than 121,000 students in the San Diego Unified School District.

The Los Angeles Unified School District, the second-largest in the nation, also shut down Monday. The district spans about 700 square miles, meaning the impact of the storm varied for its students.

Schools in the Los Angeles district will reopen on Tuesday, according to superintendent Alberto Carvalho.

“Our teams have been scouring our schools, and so far, conditions are pretty good,” Carvalho said. A couple dozen schools have lost phone and internet service, and one school has been impacted by a minor mudslide.

“It would have been reckless for us to make a different decision,” Carvalho said of the decision to close schools Monday.

“Los Angeles was tested but we came through it and we came through it with minimal impacts, considering what we endured,” said Los Angeles City Council President Paul Krekorian.

The Nye County School District in Nevada also canceled classes Monday, with plans to reopen Tuesday.

Cars stranded in roads deluged with mud and water

Once a hurricane, Hilary weakened as it made landfall Sunday in Mexico – where at least one person died – then crossed into the Golden State. The storm’s center was roughly 10 miles southeast of downtown Los Angeles around 8 p.m. local time Sunday, moving north with weakened 45-mph winds, according to the hurricane center.

The Los Angeles Fire Department fielded more than 4,000 emergency calls on Sunday and responded to about 1,800 incidents, Chief Kristin Crowley said in a news conference on Monday. The calls included a request for help for five cars stranded in a flooded intersection of Sun Valley. One person was safely rescued and no one was injured in the Sun Valley incident, Crowley said.

Flood water affected an underground power vault, leading to an outage for about 6,000 customers in the Beverly Grove area, with other outages reported in Hollywood, Hyde Park and Brentwood. The vast majority of city power customers remain unaffected by the storm, according to Los Angeles officials.

As the storm barreled through, covering roadways with debris and water, roads were blocked across Southern California by Sunday night. A section of Interstate 8 in Imperial County, east of San Diego, was closed Sunday after boulders came loose from an adjoining slope and fell into the road.

In San Bernardino County, a stretch of State Route 127 covered in floodwaters was closed, while a section of Interstate 15 was shuttered in Barstow because of downed power lines after a lightning strike, authorities said.

Traffic is slowed as water and mud from Tropical Storm Hilary covers part of Interstate 10, between Indio and Palm Springs, California, on Monday. - David Swanson/AFP/Getty Images

Crews across the region Sunday evening rescued people caught in the storm, including at least nine in a riverbed area in San Diego. “Crews are still looking for more people who may need help. #riverrescue,” San Diego Fire-Rescue said.

And Ventura County firefighters searched the Santa Clara River for people trapped in the waters on Sunday night, videos show.

The storm led to other disruptions across Southern California, with many parks, beaches and other locations closed as officials called on residents to stay indoors.

And Hilary continued to cause damage as it moved into Nevada. In Mt. Charleston, Nevada, the storm brought significant flooding on Monday morning, washing out the roadways. Residents are sheltering in place, the power is shut off, and the Nevada National Guard is on its way to assist, according to a Facebook post from Clark County.

West of Las Vegas, rushing water is flowing like a river down Echo Road, leaving vehicles stranded from Mary Jane Trailheads and Trail Canyon, according to the U.S. Forest Service. Emergency crews are evaluating and ask for people to stay out of the area, the service said.

Record rainfall in Southern California

California had been preparing for difficult conditions, positioning first responders across Southern California to brace for water rescues in flood-prone areas like wildfire burn scars and deserts amid fears areas unaccustomed to rain could suddenly receive a year’s worth or more, triggering flash floods and landslides.

Rainfall totals have been significant:

In California, Mount San Jacinto received 11.74 inches from Hilary as of Monday night, while Raywood Flats got 11.73 inches, and Heart Bar got 9.67 inches. In Nevada, Mt. Charleston received 7.80 inches and Lower Angel Peak recorded 6.52 inches.

Daily and monthly rainfall records were broken Sunday, with 1.53 inches falling in downtown Los Angeles, 1.56 inches in Long Beach and 2.95 inches in Palmdale, according to the weather service.

At least three swift water rescues were conducted in Palm Springs, police department Lt. Gustavo Araiza told CNN.

In Cathedral City, a desert community roughly a 110-mile drive east of Los Angeles, at least 14 people were rescued from a senior boarding care facility Monday afternoon after “a blockade” of mud trapped them inside, city spokesperson Ryan Hunt said.

All of the people rescued are doing well, Hunt said.

The fire department had to borrow a dozer truck from a recycling center so they could carry out the rescue, Hunt said. The department had firefighters sit in the dozer and then had those being rescued sit on top to be brought out of the structure, he added.

Despite the “unorthodox method,” everyone stayed calm, he said.

A motorist removes belongings from his vehicle after becoming stuck in a flooded street in Palm Desert, California, on Sunday. - Mark J. Terrill/AP

Santa Clarita, about 30 miles north of Los Angeles, experienced steady rain for about 10 hours, with the storm dropping well over four inches of rain on the valley. Parts of Sand Canyon Road could be seen falling into rushing water.

As the storm continues to affect the West, officials with Oregon’s emergency management are bracing for possible flooding across portions of the state.

“At this point, we’re concerned about the substantial rainfall and the potential for fast-moving water and flooding. Flood watches have been issued for areas of Central and Eastern Oregon,” Oregon Department of Emergency Management spokesperson Chris Crabb told CNN Monday afternoon.

“We have reports of minor flooding currently and communities using sandbags to mitigate the impacts, but there have been no requests for state support at this point,” Crabb went on.

According to Crabb, the office is working with county and tribal partners.

Portions of Oregon are under a flood watch through Tuesday afternoon, according to the National Weather Service.

“The remnants of Hurricane Hilary will bring periods of moderate to heavy rain to portions of northeastern Oregon through Tuesday,” the weather service said in a forecast message.

CNN Meteorologists Gene Norman and Monica Garrett and CNN’s Lauren Mascarenhas, Cheri Mossburg, Jamiel Lynch, Eric Zerkel and Sarah Moon contributed to this report.

For more CNN news and newsletters create an account at CNN.com