**Persistent marine layer conditions driven by the cold California Current and a strong temperature inversion are anchoring San Francisco’s expected daily high near 70–73°F on June 14.** This shallow layer of cool, moist marine air—capped by warmer air aloft—forms when Pacific sea-surface temperatures lag behind inland warming, producing the classic “June Gloom” stratus and fog that limits solar heating along the coast. Official forecasts from sources such as timeanddate and climate-data aggregators currently project a high of 68–72°F under scattered clouds and moderate onshore flow, aligning with the market’s heaviest probability mass on the 70–73°F (38.5%) and 70–71°F (28.5%) brackets. Climatologically, San Francisco’s June average high sits around 66–69°F at downtown and airport stations, so today’s implied range reflects a modest warming relative to the seasonal baseline without a full marine-layer breakdown. No recent model runs or observational shifts (such as strong offshore winds or a pronounced ridge) indicate rapid erosion of the inversion, keeping probabilities for 74°F+ low and those for sub-68°F modest. Traders are therefore weighting the most likely outcome near the upper end of typical June coastal readings while discounting rarer heat-spike scenarios that would require atypical synoptic changes.