With market-implied odds clustered tightly across temperature bins for Los Angeles’s lowest reading on September 2, traders are balancing the typical early-September marine layer against variable onshore flow and stratus depth. National Weather Service guidance and ensemble models highlight how persistent coastal fog and a stable inversion layer can suppress overnight lows into the upper 50s or low 60s, while any strengthening of the thermal trough or reduced cloud cover would allow radiative cooling to stall and push minima toward the mid-60s or higher. Historical climatology shows average September minima near 65°F, yet current Pacific sea-surface temperatures and upper-level ridging introduce genuine uncertainty that upcoming model updates from NOAA are expected to resolve before the observation window closes.