Singapore’s early June climatology, with average daily maximum temperatures near 31°C at Changi and other official stations, underpins the market’s emphasis on 31°C as the leading outcome. The southwest monsoon typically brings scattered afternoon showers that can cap daytime peaks around this level, while recent years have shown elevated warmth, including record June temperatures in 2025. Model guidance for mid-month 2026 indicates highs clustered between 29–32°C, with limited scope for extremes given the equatorial setting and high humidity. Traders appear to weigh these stable baseline conditions against short-term forecast variability, as National Environment Agency updates closer to the date will determine the final recorded maximum.