Recent National Weather Service guidance and ensemble model runs indicate a strengthening marine layer and persistent onshore flow will moderate temperatures across the Los Angeles Basin on August 4, keeping the official high most likely in the mid-70s. This pattern, reinforced by sea-surface temperatures near 68–70°F and a modest afternoon sea breeze, aligns with the market’s heavy weighting toward the 74–77°F range and explains why probabilities for 78°F or above remain below 20%. Short-range updates from the past 48 hours show limited warming potential, with any inland heating offset by coastal stratus that typically lingers into early afternoon. Traders are therefore treating the current forecast consensus as the dominant driver, while noting that a late clearing of the marine layer could still push readings into the upper 70s.