Daan-daang tao ang mas pinili na lamang bumaba sa mga PUV at maglakad sa Marcos Highway dahil wala nang galawan ang mga sasakyan sa lansangang ito dulot ng matinding pagbaha na dala ng malakas na pag-ulan. | via @cleonlester pic.twitter.com/TCgggibNYv

— ABS-CBN News (@ABSCBNNews) August 11, 2018

MANILA -- (UPDATE) Metro Manila and large parts of Luzon braced for more rains on Sunday as authorities surveyed the extent of floods that displaced thousands.

Rivers overflowed and dams released water due to incessant rains that started Saturday and would likely continue until the middle of the week due to the southwest monsoon, weather bureau PAGASA said.

"Yung habagat natin ngayon, malakas talaga," PAGASA forecaster Shelly Ignacio told DZMM. "Isa na ito sa pinakamalakas this year."

(This monsoon is really strong. It is one of the most intense so far this year.)

In Marikina, where the rains were likened to Tropical Storm Ondoy (Ketsana) from 2009, some 20,000 people were evacuated as 80 percent of the city was submerged, Mayor Marcelino Teodoro told ABS-CBN News.

Rubber boats were deployed to rescue trapped residents, Teodoro said as he appealed for donations of food, water, blankets, and clothes.

In San Mateo, Rizal province, some 7,794 fled to temporary shelters. Eight of its 15 barangays were inundated, said Vic Tomazar, incident commander at the municipal disaster office.

On Sunday, monsoon rains will persist in Metro Manila, Batanes, Babuyan, Ilocos Norte, Ilocos Sur, La Union, Pangasinan, Apayao, Abra, Benguet, Mt. Province, Ifugao, Kalinga and Aurora, PAGASA said. The western portions of Luzon will bear the brunt of the weather system.

• Rescue boats deployed in Marikina as river nears Ondoy level
• Calls for help fill social media as floods swamp Metro Manila
• LIST: Contact information of key gov’t agencies in case of emergency

Harried commuters were offered to spend the night in shopping malls in Marikina City, where the floods brought flashbacks of Ondoy, a tropical storm that left 464 people killed.

"Parang Ondoy ang nangyayari sa ngayon dahil sa patuloy na lakas ng ulan na binubuhos sa ganitong kaiksing panahon," Marikina Mayor Marcelino Teodoro told radio DZMM.

Na-rescue ang isang matandang lalaki, manugang niya, at apo matapos hindi makalabas ng bahay nang malubog sa baha ang Twinville Subd., sa Brgy. Nangka, Marikina City | via @Dennis_Datu pic.twitter.com/FnUeLKgoo3

— ABS-CBN News (@ABSCBNNews) August 11, 2018

Lebel ng tubig sa Marikina River, 20.6 meters na (as of 10 pm). 📹: Ian Angeles pic.twitter.com/Ye7k4f9Xvu

— ABS-CBN News (@ABSCBNNews) August 11, 2018

One gate of Ipo Dam in Bulacan was opened at midnight. It will affect the towns of Norzagaray, Angat, San Rafael, Bustos, Pulilan, Plaridel, and Hagonoy, said PAGASA hydrologist Jason Bausa.

San Roque Dam in Pangasinan will be opened at 2 a.m., Bausa said without specifying how many gates. It will affect the towns of San Manuel, San Nicolas, Tayug, Asingan, Sta. Maria, Villasis, Alcala, Bautista, Rosales, and Bayambang.

Gates on Ambuklao, Binga and Magat dams were opened earlier Saturday, he said.

TINGNAN: Binaha rin ang Sta. Filomena sa Guagua, Pampanga; nasa 60 barangay na sa Pampanga ang lubog sa baha dahil sa pag-ulan | via Gracie Rutao pic.twitter.com/l4IVvrW5Wd

— ABS-CBN News (@ABSCBNNews) August 11, 2018

Non-stop rains submerged cars, stranded thousands, and blanketed the capital in darkness for much of the day Saturday. But that did not stop some from going about their day.

• WATCH: Floods hit parts of Quezon City, Rizal

In Hagonoy, Bulacan, a determined bride got her veil and dress wet walking down a flooded aisle to meet her groom.

In Quezon City, a casket was left to float on Styrofoam so that the wake of a 20-year-old man who died of a heart attack could proceed.

- with a report from Dennis Datu, ABS-CBN News