The provincial Civil Defence Command has asked local authorities and relevant agencies to prepare for heavy rain, flooding, flash floods, landslides, strong winds, lightning, hail and other hazardous weather.
Authorities have been told to inspect riverside, low-lying and landslide-prone areas and evacuate residents where necessary, particularly in places already affected by heavy rain.
Local forces will also monitor flooded roads, spillways and areas at risk of landslides, restricting access where conditions are unsafe.
Militia and police will patrol high-risk routes, particularly National Highways 27C and 27, and stand ready to respond to landslides, falling trees and rocks, and traffic disruption.
Nguyen Duy Quang, director of the provincial Department of Agriculture and Environment, said reservoir operators had been told to follow approved procedures and strengthen safety checks and downstream warnings.
Any floodwater releases must be announced in advance, with information on timing, discharge volumes and areas likely to be affected, he said.
The province has also drawn up a contingency plan for rainfall of 200-500 mm within 24 hours if a storm or tropical depression combines with strengthening cold air.
Under that scenario, river levels could rise more than one metre above the highest warning level, potentially reaching or exceeding historic flood levels and causing widespread flooding, flash floods and landslides.
Evacuation plans cover three scenarios, ranging from more than 73,600 people if rivers exceed the highest warning level to nearly 120,000 in the event of historic flooding.
Khanh Hoa is forecast to receive 120-250 mm of rain from September 21 to 24, with more than 300 mm possible in some areas and over 100 mm within three hours in isolated locations.
