With outcomes clustered tightly between 66–73°F, Polymarket traders are reflecting genuine forecast uncertainty in the precise overnight low for Los Angeles on August 30. The marine layer—cool, moist air flowing onshore from the Pacific—remains the dominant control on minimum temperatures, its depth and timing varying with subtle changes in the subtropical high-pressure ridge and onshore flow strength. Recent model runs show modest disagreements on inversion strength and coastal fog coverage, which can suppress or elevate lows by 2–4°F depending on whether the layer reaches downtown or the airport by dawn. Historical late-August climatology places typical minima near 66–68°F, but weak onshore gradients this week have allowed slightly warmer readings in recent nights, keeping the 70–71°F bin narrowly ahead while leaving room for revision as final NWS observations are recorded.