Recent National Weather Service and ensemble forecasts for downtown Los Angeles indicate September 1 overnight lows centered in the mid-60s°F amid persistent high pressure and light onshore flow, though model spreads allow for stronger marine-layer cooling or residual warmth from the late-August heat wave. Sea-breeze timing, boundary-layer mixing, and dew-point advection from the Pacific create the primary uncertainty differentiating the tightly bunched mid-range bins; historical September 1 lows average near 65°F with a standard deviation that routinely spans the 60–70°F range. With resolution imminent, traders are weighting the latest NWS point forecasts and rapid-update model runs that could still shift implied probabilities if a deeper marine push materializes.