The Nadi weather office states heavy rain will develop across the country from later today.
A heavy rain warning is in force for the whole country, alongside a flash flood alert for all small streams and low-lying flash flood prone areas of Fiji.
The weather office says rain bands associated with Tropical Cyclone Seru is expected to bring rain over most parts of the group from today.
The forecast is for cloudy periods with some showers and isolated heavy falls over the Western and Northern Divisions including Kadavu and Southern Lau group.
Showers expected to increase to rain and become frequent from today.
In other parts of the country, there will be afternoon or evening showers with isolated heavy falls and thunderstorm and showers will increase to rain from later today.