There could be localised flash floods this weekend and early next week, if high tides meet heavy rain.
The highest tides will range from 3.3 to 3.4 metres in the late morning and early Saturday afternoon to Tuesday.
Afternoon showers are also expected over the next few days, said the PUB and National Environment Agency.
If the two occur at the same time, flash floods could hit low-lying coastal areas such as Fort Road and Meyer Road that are influenced by tides. And canals that open directly into the sea, such as Bedok Canal and Siglap Canal, will have high water levels.