**Active southwest monsoon (habagat) and scattered thunderstorms over Luzon are the main drivers keeping overnight minimum temperatures in Manila near or slightly below normal for late August.** Persistent cloud cover and high humidity from the monsoon limit radiative cooling at night, while localized heavy rain and moderate-to-strong southwest winds further moderate the diurnal range. Official PAGASA guidance and ensemble forecasts for 26 August indicate overnight lows typically between 24–27 °C, consistent with climatological averages around 26 °C, though model spread and variable thunderstorm timing create uncertainty about whether stronger cooling or retained cloud heat will prevail. Distant tropical systems east of the Philippines may enhance monsoon flow, but no direct landfall is expected by 26 August. Traders appear to weigh the balance between potential clear-sky cooling episodes and sustained cloud/rain suppression of minimum temperatures, producing closely matched probabilities for both cooler and warmer extremes.