Forecast models from the National Weather Service and private outlets converge on a high near 77–79°F for Chicago on August 14, driven by a cooler-than-normal air mass, widespread cloud cover, and light northeast flow limiting daytime heating. This places the most likely outcome slightly below the long-term normal of about 83°F and explains why the 78–79°F bin holds the highest market-implied probability (29.5%), followed closely by 80–81°F. Key variables that could shift the result include the exact timing of any afternoon clearing or weak warm advection; stronger insolation would favor the 82–83°F range, while persistent stratus would cap readings nearer 76–77°F. Updated NWS guidance and high-resolution model runs expected overnight will provide the final resolution inputs before markets close.