Dry Conditions and Haze Advisory September 2026

The National Environment Agency (NEA) reported on 1 September 2026 that the Southwest Monsoon was expected to bring below-average rainfall over most of Singapore during the first fortnight of September. The advisory is a forecast for 1–15 September, not a retrospective statement that every part of Singapore would receive the same rainfall or temperature (NEA, 1 September 2026).

Forecast temperatures and rainfall boundary

NEA forecast daily maximum temperatures of about 33°C to 35°C on most days (the forecast range is 33°C and 35°C), with daily minimum temperatures generally above 27°C. The forecast should not be read as saying that every day or every location would exceed 35°C. For context, NEA reported that the 17–31 August 2026 period had an island-wide average rainfall 99% below average, while the highest temperature recorded was 35.5°C at Seletar; those are observations for the preceding period, not September predictions (NEA, 1 September 2026).

Regional smoke and haze risk

NEA said regional smoke-haze conditions could affect Singapore if fires in southern and central Sumatra and Kalimantan intensified and winds carried the smoke towards Singapore. The relevant wind pattern was described as southeasterly or southwesterly winds. This is a conditional transport-risk assessment, not a declaration of a confirmed nationwide pollution episode on 1 September or that regional fires would necessarily affect all locations (NEA, 1 September 2026).

PSI monitoring and daily advisories

NEA said it would issue daily haze advisories if the 24-hour Pollutant Standards Index (PSI) reached the Unhealthy range. The trigger concerns the official 24-hour PSI and an advisory process; it is not a rule that visible haze, smell, or a third-party air-quality index automatically means the Unhealthy band has been reached. People should use NEA's official air-quality updates for the current reading and health guidance (NEA, 1 September 2026; haze).

Interpretation and date boundary

This advisory combines a weather outlook with monitoring arrangements for possible transboundary smoke. It does not itself establish a new haze law, declare a confirmed island-wide pollution episode, or convert the rainfall figures into a national climate statistic. Later NEA readings and advisories should supersede this dated forecast when answering what conditions actually occurred after 1 September 2026 (NEA, 1 September 2026).

4 September 2026 haze response

On 4 September 2026, NEA reported that the 24-hour PSI reached 101, the Unhealthy range, in the central region at 7am. NEA said this was the first haze-related entry into the Unhealthy range since 8 October 2023. The Haze Task Force rolled out agency action plans, and NEA began issuing daily haze advisories from the evening of 4 September with a 24-hour PSI forecast for planning activities (NEA, 4 September 2026).

The response included population-specific guidance rather than a universal closure rule. NEA and partner agencies advised reducing prolonged outdoor activity and strenuous exercise, while schools, preschools, workplaces, healthcare institutions and sports organisers were directed to follow the relevant air-quality and health guidance. Current readings and advisories were made available through haze.gov.sg, NEA and the myENV app; later readings and advisories supersede the 4 September snapshot (NEA, 4 September 2026).