Recent National Weather Service model runs and local observations point to a stable marine layer and light onshore flow maintaining overnight lows in the mid-60s across Los Angeles on September 18. Clear to mostly clear skies are expected after any morning fog, supporting modest radiational cooling but limiting deeper drops. Ensemble guidance clusters around 63–65 °F at coastal and valley stations, consistent with the September climatological normal of 63–64 °F and recent days’ observed minima near 65 °F. Traders therefore assign the highest implied probabilities to the 64–65 °F and 66–67 °F bins, while lower-probability outcomes below 60 °F would require an unexpected strengthening of offshore winds or clearer, drier air that current guidance does not support.