SINGAPORE - The National Environment Agency (NEA) on Saturday issued a heavy rain alert, with national water agency PUB adding that flash floods may occur in the event of heavy rain.

At 4.22pm, PUB said the water level in its measuring station at Veerasamy Road in Little India had risen to 100 per cent.

Over in the west, water levels were rising, too. PUB tweeted about high flood risks at Tanjong Penjuru and Penjuru Road at 4.31pm.

Moderate to heavy thundery showers, accompanied with gusty wind, were expected over many areas of Singapore between 3pm and 4pm.

NEA's two-hour weather forecast showed rain, some with thundery showers, over most of the island except the southern tip.

Temperatures for Saturday were expected to range between 24 deg C and 33 deg C.

Afternoon thundery showers are expected for the next four days, as well.

Singapore is currently experiencing inter-monsoon conditions, characterised by warm weather and thunderstorms, at times intense, in the afternoons and evenings.

Lightning activity tends to be higher during the inter-monsoon months.