**Trader consensus on the lowest temperature in Manila on September 1, 2026, clusters tightly around 26–28°C because current forecasts and the active southwest monsoon (habagat) point to overnight lows in that narrow range amid persistent cloud cover and scattered showers.** Official Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) guidance and multiple numerical models show September 1 conditions dominated by moderate-to-strong southwesterly flow, high humidity (75–90%), and widespread cloudiness that limits nocturnal radiative cooling. Typical September climatology places average nighttime minima near 25–26°C; the monsoon’s moisture and cloud deck usually prevent drops much below this while also capping daytime maxima around 29–31°C. Detailed hourly outputs for the date show readings stabilizing near 26–27°C in the early morning hours before rising, with only modest variability across ensembles. Differentiating factors among the leading outcomes include the precise timing and intensity of any showers (which can suppress cooling further or allow brief clearer periods), exact cloud fraction overnight, and minor steering influences from distant systems like Tropical Depression Pilandok well east of Luzon. Stronger or more persistent monsoon rains would favor the higher end (27–28°C) by maintaining a warmer boundary layer, while any temporary reduction in cloud cover could permit slightly lower readings near 25–26°C. Extreme tails (below 24°C or 30°C+) remain low-probability given the entrenched monsoon pattern and lack of major tropical cyclone threats in the immediate forecast window. Updated model runs and PAGASA briefings over the next 48 hours will provide the key signals for any shifts in these tightly bunched probabilities.