The active southwest monsoon dominates trader sentiment for Manila's August 27 overnight low, sustaining thick cloud cover, scattered thunderstorms, and moderate-to-strong southwesterly winds that limit radiative cooling and keep temperatures from dropping sharply. Official forecasts and recent observations place the minimum near 26–27°C, consistent with historical August averages of 25–26°C under similar monsoon conditions, while urban heat retention and high humidity further suppress extremes. Market probabilities cluster tightly between 24–28°C because models show modest uncertainty in precipitation timing and wind mixing, which can shift the exact low by a degree or two; cooler outliers would require unusually clear skies or stronger winds, scenarios not currently favored by PAGASA guidance or ensemble runs.