**Marine layer moderation and post-heat-wave cooling are anchoring trader expectations for a downtown Los Angeles high near 80 °F on August 21.** Persistent onshore flow from the Pacific has kept coastal and basin temperatures well below inland peaks, with National Weather Service guidance showing highs around 78 °F for the immediate Los Angeles area in the current forecast period. This aligns with the market’s heaviest concentration on the 78–81 °F bins (combined ~77.5 % implied probability). After an extreme heat ridge that produced triple-digit readings across much of Southern California in late July and early August, the pattern has shifted toward more typical late-summer conditions. The marine layer and associated stratus have strengthened, limiting daytime heating even as seasonal solar input remains high. Historical August normals for downtown Los Angeles hover near 84 °F, yet recent model runs reflect stronger-than-average onshore pressure gradients that favor the lower end of the climatological range. Key variables traders are monitoring include the depth and persistence of the marine layer overnight, any subtle warming aloft that could erode it, and the next NWS forecast discussion or model update, which can rapidly shift probabilities in coastal zones. The tight clustering around 80 °F reflects both current observational trends and the recognition that small changes in boundary-layer moisture or wind direction could still push the daily maximum a degree or two in either direction before resolution.