**Marine layer influence and post-heat wave cooling are positioning 78-79°F as the clear market favorite for Los Angeles’ highest temperature on August 31.** Official National Weather Service and private forecasts consistently project highs in the upper 70s to mid-80s, with the strongest consensus around 78–82°F once morning low clouds and fog clear. A weakening heat dome and strengthening onshore flow from the Pacific have introduced a deeper marine layer, which limits afternoon heating through cloud cover and cooler boundary-layer air—conditions that historically cap coastal and basin temperatures near or slightly above the 76.8°F long-term average high for the date. Recent model runs and NWS point forecasts for LAX and downtown show highs near 78–85°F, with any higher readings dependent on earlier clearing or slightly stronger offshore flow. The 80–81°F bin sits as the next most likely outcome if marine effects are weaker than expected, while the low probability assigned to 82°F+ reflects the current forecast consensus for moderation. Updated guidance on marine layer depth and timing over the next 48 hours will be the key variable for traders.