Persistent southwest monsoon flow over the Philippines is the dominant driver keeping Manila's overnight lows elevated on August 28, with PAGASA and GFS/ECMWF guidance showing widespread cloud cover, scattered thunderstorms, and high humidity that limits radiative cooling. Forecast minimums cluster tightly around 25–27 °C (roughly 77–81 °F), as moist southwesterly winds and 80–95 % relative humidity reduce the typical 5–7 °C diurnal range. Historical August baselines near 25.6 °C provide context, but active convection and the absence of clear-sky conditions this week tilt probabilities away from sub-24 °C readings while capping upside potential above 28 °C. Updated model runs and PAGASA briefings through August 27 will refine the exact minimum, with traders weighting wind speed and precipitation timing as key variables that can shift the overnight low by 1–2 °C.