Recent National Weather Service guidance and ensemble models indicate a warm southerly flow advecting air with temperatures several degrees above the early-June climatological normal of 78°F at Chicago’s O’Hare station. This pattern supports peak readings most likely in the mid-80s, with the tightest clustering of market-implied odds between 84–87°F reflecting model consensus on maximum temperatures while acknowledging typical 2–3°F forecast spread from boundary-layer mixing, cloud cover timing, and lake-breeze effects. Limited precipitation risk and strengthening southwest winds further favor the higher end of the distribution, though any overnight clearing or stronger lake moderation could pull readings toward the lower 80s. Updated model runs and the final NWS forecast issued overnight will provide the last major data point before resolution.