**Cooler-than-normal conditions driven by persistent high pressure over the Hudson Bay region are keeping Chicago temperatures below the 83°F June 25 climatological normal.** Official extended outlooks and recent model guidance point to a high near 75–78°F, aligning with the market’s heaviest trading in the 76–79°F bins. Key variables include the strength and position of the ridge, which favors northerly flow and limited mixing; potential afternoon cloud cover or weak frontal boundaries that could cap daytime maxima; and any timing shifts in steering patterns that might allow brief warming. With uncertainty remaining in 48-hour model runs from NOAA and NWS Chicago, traders are weighting the most likely mid- to upper-70s range while assigning lower probability to an 80°F+ spike or a sharper cool-down. Updated short-range forecasts and afternoon model cycles will provide the next resolution signals.