Singapore is expected to experience increased rainfall and warm temperatures during the second half of September, according to the Meteorological Service Singapore's (MSS) forecast released on September 16. Showers are anticipated to be more frequent compared to the first half of the month, with short and thundery showers likely to occur from late morning to afternoon on most days. The MSS also expects one or two days of widespread moderate to heavy thundery showers across the island.

Overall, total rainfall for the period is predicted to be near the long-term average for most parts of Singapore. Daily maximum temperatures are forecast to range between 33°C and 34°C, with occasional peaks reaching up to 35°C. Night-time temperatures are expected to remain warm and humid, with minimums staying above 27°C on certain nights.

The prevailing south-west monsoon conditions will continue to influence the weather, bringing winds mainly from the south-east or south-west directions. This pattern contributes to the increased likelihood of showers and elevated humidity levels.

Reflecting on the first half of September, the MSS noted that weather conditions were mostly dry, with brief thundery showers occurring in parts of the island on select days. On September 11, the island experienced its most significant rainfall event of the fortnight, with moderate to heavy showers affecting many areas during the late morning and afternoon. This was attributed to regional wind convergence. Scotts Road recorded the highest daily rainfall total at 105 millimeters that day and also saw the lowest temperature of 22.4°C at 3:51 p.m.

Despite this rainfall event, overall precipitation levels for the first half remained well below average. The Changi area, for instance, registered rainfall approximately 98 percent below its historical average for this period. Temperatures during the first half were predominantly warm, with daily highs exceeding 34°C on 12 days. The peak temperature recorded was 35.3°C at Sembawang on September 9. Night-time temperatures consistently stayed above 27°C across many parts of the island, maintaining humid conditions.

The MSS advises residents to prepare for variable weather in the coming days, keeping umbrellas handy due to the expected increase in showers, while continuing to expect warm temperatures throughout the rest of September.