Trader consensus on the 68-69°F outcome for San Francisco’s June 15 high reflects National Weather Service forecasts and the city’s persistent marine-layer influence, which caps daytime temperatures through onshore flow and coastal stratus. June climatology shows average highs near 68-70°F at official stations like KSFO, with fog and upwelling typically suppressing readings above the mid-70s. Pre-event model runs aligned closely with this range, producing minimal dispersion and driving near-certain market pricing. A rapid marine-layer erosion or anomalous offshore flow could have allowed readings into the low 70s, yet no such shift materialized in the final observational data.