Recent forecasts from Singapore's Meteorological Service and international models indicate a daily maximum near 31–34°C on September 29, driven by persistent warm, humid conditions under the southwest monsoon with southeast winds. Afternoon thundery showers—common in the second half of September—introduce the main uncertainty, as their timing, coverage, and intensity can limit solar heating and cap peaks or allow brief spikes above 33°C before cooling. Historical September maxima often reach 33–34°C when convection is delayed, while earlier or widespread storms favor 30–32°C; this narrow spread of plausible outcomes, combined with local station variations, explains the tightly clustered market-implied probabilities around 30–34°C. Updated model runs and official briefings over the next 48 hours will refine the range.