Recent National Weather Service guidance projects a daytime high of 66-67°F in San Francisco on May 16 under a moderate marine layer and persistent onshore westerly flow that restricts afternoon solar heating and keeps boundary-layer mixing shallow. This setup aligns with mid-May climatological averages near 67°F at the airport station, where stratus clouds and 15-20 mph breezes typically cap peaks below 68°F. Model consensus shows minimal high-pressure influence, reinforcing trader confidence in the narrow range. Real-time observations through evening could still shift the outcome if unexpected clearing allows brief warming, though current atmospheric conditions make such deviations unlikely.