Recent National Weather Service and model guidance point to a strengthening marine layer and persistent onshore westerly flow bringing cooler Pacific air into the Bay Area, limiting daytime heating for San Francisco on August 29. After highs near 70–75°F earlier in the week, forecasters now expect partly to mostly cloudy conditions with west winds of 10–20 mph, producing a high most likely in the mid-60s—consistent with the closely matched market probabilities for 66–67°F and 68–69°F. Key variables include the depth and persistence of low stratus or fog, which can suppress maximum temperatures by several degrees, versus any brief clearing that allows modest solar warming. Historical late-August averages near 70°F provide context, but current atmospheric patterns favor the lower side of the distribution, with limited upside risk from tropical moisture or model shifts.