**Current forecasts from multiple sources, including NWS-aligned models, point to a Tuesday night low in the mid-to-upper 60s°F for Los Angeles, aligning with the market's leading 68-69°F bucket at 46.5% implied probability.** Recent daily lows have hovered in the mid-to-upper 60s amid generally clear to partly cloudy conditions and light onshore flow, keeping overnight cooling moderate. The primary scientific drivers include the strength and timing of the marine layer—the shallow, cool, moist air mass from the Pacific that often produces low clouds and fog, limiting radiative cooling and capping how low temperatures drop. Sea surface temperatures remain near or above seasonal norms, reducing the thermal contrast that strengthens this layer, while light winds and variable cloud cover influence the exact minimum. Historical averages for September 15 sit near 64°F, but recent patterns show slightly milder nights when marine influence is weaker. The close contest with the 61°F-or-below outcome (40.5%) reflects uncertainty in boundary-layer details: stronger onshore flow or thicker stratus could push the low lower, while clearer skies and lighter winds allow more cooling toward the 68-69°F range. Forecasters note typical model spread in these coastal regimes, with updates from the National Weather Service and refined runs expected to clarify the overnight minimum before resolution.