Recent National Weather Service and model guidance indicate overnight lows in the mid-60s for Los Angeles on September 18, driven by persistent marine-layer influence and light onshore flow from the Pacific that moderates radiational cooling. Clear to partly cloudy skies after morning fog allow some surface heat loss, yet proximity to the cool ocean and typical September dew points near 60°F limit the minimum. Microclimate differences across the basin, variable wind speeds, and exact fog timing introduce uncertainty in the precise hourly low, explaining trader focus on the 64–65°F range alongside higher outcomes. Updated model runs and evening observations will refine these thresholds before resolution.