**Trader sentiment reflects substantial forecast uncertainty for the overnight low in Los Angeles on August 27, 2026, with probabilities clustered around 66–77°F and no single range exceeding 26%.** Current National Weather Service and private model guidance points to lows in the lower to mid-70s under mostly cloudy skies, consistent with late-August conditions in the Los Angeles Basin. Key scientific drivers include the depth and strength of the coastal marine layer—a cool, moist boundary-layer air mass advected onshore by the typical southwest flow. This layer, capped by a subsidence inversion from the Pacific high, limits nocturnal radiational cooling; thicker or cloudier marine air keeps surface temperatures higher (near 72–75°F), while a shallower or clearer layer allows more cooling toward the mid- to upper 60s. Cloud cover, dew-point temperatures near 65–68°F, and light winds (generally under 10 mph overnight) further modulate the rate of temperature drop, as does the precise timing of any clearing. Recent model runs show modest disagreement on inversion height and low-cloud persistence for the night of August 26–27, producing the tight clustering of market probabilities. Historical August norms at coastal stations (e.g., LAX) feature overnight lows around 65–68°F, but persistent onshore flow and elevated marine influence this week have supported warmer minima. No major synoptic shifts (such as strong offshore Santa Ana winds) are expected before resolution, leaving the outcome sensitive to the next few forecast updates.