Official National Weather Service forecasts call for sunny conditions and a daytime high near 73°F in San Francisco on May 17, placing the 68°F-or-higher outcome at 73% implied probability. Springtime solar insolation combined with minimal onshore flow from the Pacific has suppressed the typical marine layer, allowing temperatures to climb several degrees above the May climatological average of 65–68°F. Model guidance shows little spread, with the main variables being exact timing of peak heating and localized fog intrusion near the coast. Traders are weighting the consensus forecast heavily because resolution depends on a single official maximum reading, and recent days have already demonstrated similar clear, warm patterns without significant deviations.