Latest National Weather Service guidance and ensemble model runs indicate a high near 80°F for downtown Los Angeles on September 5, driven by moderate onshore flow and a shallow marine layer that limits daytime heating along the coast. Persistent southwesterly winds and patchy low clouds or fog in the morning further suppress temperatures compared to typical September climatology. The narrow spread between the leading 78–79°F and 80–81°F bins reflects uncertainty in exact cloud timing and boundary-layer mixing depth, with slightly stronger sea breezes or earlier marine intrusion favoring the lower outcome. Inland stations could run several degrees warmer, but coastal observations and official resolution criteria anchor the market-implied odds near the 79–81°F range. Updated model runs and the evening forecast discussion will clarify whether any late-day clearing allows a brief push above 81°F.