A SLIGHT haze across Singapore on Friday morning should dissipate by late afternoon, the National Environment Agency (NEA) has said.

The NEA said the haze could have resulted from "weak and converging winds" over Singapore in the morning, but rain in the afternoon is expected to disperse it.

Rain is also expected in Sumatra, Indonesia in the afternoon, which should reduce the number of fires there causing the haze, it said.

As of 2pm, the health advisory remains in the good and moderate band, so people can carry on with their normal activities, the NEA said. It will also continue to monitor the situation closely, and issue another advisory should conditions take a turn for the worse.

The 24-hr PSI reading as at 11am is 29-39, in the good range, and the 24-hr PM2.5 reading is 20-27 micrograms per cubic metre, which means only unusually sensitive people should reduce heavy or prolonged exertion.