SINGAPORE - Expect a slightly wetter September, the National Environment Agency (NEA) has said.

Slightly hazy conditions can be expected over the weekend if fires emerge in Sumatra, it added.

For the next weeks, winds are forecast to blow mainly from the south-east or south-west, and from the west on a few days.

The rainfall for the first fortnight of September is likely to be slightly above normal, NEA said.

Singapore can also expect five to seven days of short, thundery showers.

These will mostly be in the late morning and afternoon, and are due to "strong solar heating of land areas coupled with wind convergence", NEA said.

In addition, showers with thunder and occasional gusty winds can be expected on one or two days in the early morning.

They are due to squall lines moving eastwards from the Strait of Malacca.

Dry and warm weather conditions can still be expected on a few days where the daily maximum temperatures could reach around 34 deg C.

On most days, the daily maximum temperatures are forecast to range between 32 deg C and 33 deg C.

The Pollutant Standards Index (PSI) for Friday is forecast to be in the moderate range. The one-hour PM2.5 concentration is expected to be normal.

A total of eight hot spots were detected in Sumatra, and there was no visible haze seen there on Thursday.