Recent National Weather Service and private model consensus for San Francisco on September 19 points to a daily maximum near 68–69 °F under partly cloudy skies with moderate onshore southwest flow, keeping the marine layer in place and limiting afternoon warming. This aligns with the month’s typical climatology, where average highs reach about 71 °F, while recent days have hovered in the mid-to-upper 60s amid persistent westerly winds and coastal stratus. Traders have placed the highest implied probability on 70–71 °F, reflecting modest upside potential if clearing occurs earlier than expected or if a brief offshore component develops. Key resolution hinges on the official maximum recorded at downtown or airport stations; updated model runs tonight and morning observations will determine whether probabilities shift toward the 68–69 °F or 72–73 °F bins.