Recent National Weather Service and model guidance for San Francisco on October 8 points to a daily minimum in the upper 50s, shaped by the persistent marine layer and onshore westerly flow that limits overnight radiational cooling along the coast. This contrasts with the ongoing inland heat wave, where temperatures remain elevated but San Francisco’s microclimates keep readings closer to seasonal norms near the historical average low of 55°F. Trader sentiment reflects genuine forecast uncertainty around exact marine intrusion timing and cloud cover, which can shift the minimum by several degrees; the wide distribution across mid-50s to low-60s bins captures this variability, while the low probability on sub-50°F outcomes aligns with the absence of strong cold-air advection in current runs. Updated model guidance and NWS briefings through October 7 will likely refine these odds.