Marine layer moderation combined with post-heat-wave cooling is anchoring trader expectations for a Los Angeles high near 80°F on August 21, as persistent onshore flow from the Pacific keeps coastal and basin temperatures below inland peaks. National Weather Service guidance currently projects highs around 78°F for the immediate Los Angeles area, aligning with the market’s heaviest concentration on the 78–81°F bins (combined ~78% implied probability). This setup reflects typical late-summer patterns where the marine layer suppresses daytime warming along the coast, following recent elevated temperatures driven by a stronger Western ridge. New model runs and updated NWS forecasts over the next 24 hours represent the key variables that could shift probabilities if onshore flow weakens or the layer thins.