Trader consensus on Polymarket closely splits between 31°C (31%) and 32°C (31.5%) as Singapore's highest temperature on April 17, reflecting uncertainty in how afternoon thundery showers—forecast by the Meteorological Service Singapore (MSS)—will cap peak heating amid inter-monsoon conditions with light southerly winds at 5-15 km/h. MSS's latest 4-day outlook projects a 33°C maximum (19% implied probability), but late morning and early afternoon showers could reduce solar insolation during the critical 12-2 pm window when urban heat islands typically drive station highs, potentially suppressing readings to the 31-32°C range seen in recent rainy days this April. April's climatological average high is 31.7°C, with early-month peaks reaching 34.5°C under clearer skies; twice-daily forecast updates will clarify shower intensity and timing before resolution.