National Weather Service forecasts and major model ensembles project a high near 70°F in Denver on May 17 under partly cloudy skies and light northerly flow, establishing the 71°F-or-below outcome as the clear market leader at 85% implied probability. This cooler reading relative to the May 17 climatological normal of 72°F stems from the eastward progression of a mid-level trough that replaced the recent upper-level ridge, allowing a cooler continental air mass to settle over the Front Range while limiting daytime heating and solar insolation. Ensemble guidance shows tight agreement on peak temperatures, with only modest uncertainty from variable afternoon cloud cover that could trim readings a degree or two lower. Traders will watch the next model updates and surface observations at Denver International Airport as the market approaches resolution.