Official forecasts from Russia's Hydrometeorological Center established the primary driver for trader consensus around a 13°C daily maximum in Moscow on September 7, 2026, citing persistent cloud cover, light to moderate rain, and northwesterly winds of 7–12 m/s that limited daytime warming. These conditions aligned with observed surface temperatures ranging from +11°C to +13°C, well below the 1991–2020 climatological average high of 18.1°C, reflecting a cooler early-September pattern following a record-warm summer. Market-implied odds near 100% for 13°C reflect aggregated trader assessment of station data resolution criteria, with low probabilities on adjacent thresholds acknowledging minor uncertainties in exact peak timing or localized variations. Realistically, only revised official observations or post-event quality control adjustments could alter the outcome.