Official NWS and model guidance point to an overnight low near 65°F in Denver on August 28 under partly cloudy skies with only a 10-20% chance of showers, consistent with the market’s tight clustering around 64-69°F. Primary scientific drivers include reduced radiative cooling from variable cloud cover, dew points in the upper 40s to low 50s limiting further temperature drops, and light southwest winds that limit boundary-layer mixing. Traders weigh minor forecast spreads from differing model timing of any clouds or showers, plus Denver’s urban heat island and 5,280-foot elevation, which can shift the exact minimum by a degree or two. Historical August lows average 56°F, but recent warm, dry conditions support the current higher range.