Persistent southwest monsoon (habagat) conditions over Metro Manila, with cloudy skies and scattered rains or thunderstorms expected on August 15, are the main factors capping maximum temperatures near the long-term August average of 31°C. Official PAGASA guidance and ensemble models indicate highs most likely between 30–33°C, consistent with reduced insolation from widespread cloud cover and frequent precipitation that limits daytime heating. The market's heavy weighting toward 30–32°C reflects this consensus, with traders assigning low probability to extremes above 33°C or below 30°C given typical monsoon thermodynamics and the absence of clear-sky or subsidence-driven heat buildup in recent forecasts. Updated model runs and PAGASA briefings on monsoon intensity remain the key near-term catalysts for any shifts in implied probabilities.