The Southern Regional Hydrometeorological Centre forecasts peak water levels of 1.7-1.75 metres at Phu An and Nha Be stations, exceeding warning level 3 by 10-15 centimetres.
At Thu Dau Mot station, tides could reach 1.8-1.85 metres, or 20-25 centimetres above the highest warning threshold.
Peak tides are expected between 5 am and 7 am and again between 5 pm and 7 pm during October 26-28.
Water levels across the city's rivers and canals are forecast to rise over the coming days as the lunar tidal cycle intensifies.
Forecasters warned that high tides combined with rainfall could inundate low-lying neighbourhoods and riverside roads, disrupting traffic and daily activities.
Residents have been advised to monitor weather and flood warnings and take precautions.
Meanwhile, scattered showers and thunderstorms are forecast across HCM City and southern Vietnam on October 23, with temperatures ranging from 23 to 34 degrees Celsius.
