Prevailing southwest monsoon conditions are keeping Singapore's overnight lows elevated during the second half of August, with the Meteorological Service Singapore noting most nights staying above 27°C amid high humidity and limited radiative cooling. This underpins the tight clustering of market-implied odds around 27–28°C for the August 26 minimum, consistent with climatological baselines of 25–27°C and recent model guidance showing daytime highs of 33–34°C. Key variables that could shift the exact low include localized thundery showers, which may enhance or suppress nocturnal cooling depending on timing and coverage, along with subtle variations in wind and cloud cover. Official forecasts emphasize uncertainty ranges typical of tropical environments, where small atmospheric changes can alter the daily minimum by 1–2°C.