**Trader sentiment for San Francisco’s June 17 high temperature centers on the interplay between the persistent marine layer and variable onshore flow.** Official forecasts from sources like the National Weather Service and models point to a typical early-summer pattern, with morning stratus and moderate westerly winds limiting daytime heating at KSFO. This keeps the most likely peak in the upper 60s to low 70s, explaining why the 70-71°F and 72-73°F bins dominate with closely matched probabilities. Subtle differences hinge on the exact timing of any afternoon clearing, wind speeds (stronger flow enhances evaporative cooling), and boundary-layer mixing; even modest reductions in cloud cover or a brief wind lull can add 1–2°F. Historical June averages near 67°F and the absence of strong offshore or downslope warming reinforce the tight clustering around these outcomes, with later-day observations likely to decide the narrow spread.