Current National Weather Service and AccuWeather forecasts for San Francisco on August 22 point to overnight lows in the mid-to-upper 50s, aligning with the market’s leading ranges of 58-59°F, 56-57°F, and 54-55°F. Persistent marine-layer stratus and moderate onshore westerly flow off the Pacific are the dominant factors suppressing nighttime radiative cooling and holding temperatures near the August climatological average of 57°F. Recent model runs show no significant warming or cooling trend through the weekend, with high pressure over the interior West maintaining the typical summer pattern of coastal fog and stable marine air. Traders appear to be weighting these consistent guidance signals heavily, while assigning low probability to outlier scenarios such as stronger offshore flow or clear-sky radiational cooling that could push the low outside the 54–59°F window.