Trader consensus around the 66-67°F outcome for San Francisco’s highest temperature on June 9 reflects verified National Weather Service observations confirming that peak reading at official stations. NOAA forecast models converged on this narrow range in the days leading up to the date, driven by a persistent marine layer that suppressed daytime warming under typical early-summer conditions. Climatological baselines for the first week of June show mean highs near 65–68°F with low variability, aligning with the market-implied odds. Any post-observation revision remains unlikely absent measurement discrepancies, as multiple sensors reported consistent values within the threshold.