Current forecasts from the National Weather Service and major models indicate an overnight low in San Francisco on August 25 most likely in the upper 50s, driven by persistent marine layer stratus, moderate onshore westerly winds, and typical late-summer coastal cooling that limits radiative heat loss. This pattern aligns with historical August averages near 58°F and explains the market’s concentration on 56–59°F bins. Minor model spread around cloud cover and wind speed keeps 54–55°F as a plausible tail outcome, while warmer readings above 60°F appear unlikely absent a sharp offshore flow shift. Updated NWS briefings and next model runs remain the key near-term catalysts for any adjustment in implied probabilities.