**Forecast models from Russian meteorological services and international sources such as GFS indicate a highest temperature of 17–18°C for Moscow on September 13, 2026, under partly cloudy skies with light westerly winds and minimal precipitation risk.** This aligns with the market’s leading outcomes, where 17°C holds the highest implied probability at 45.5%, followed by 16°C (21.5%) and 18°C (19.5%). The primary scientific drivers include the seasonal decline in solar insolation during early autumn, combined with a westerly flow that advects relatively mild air from the Atlantic. This setup keeps daytime maxima near or slightly above the 1991–2020 climatological average high of approximately 16.9°C, while overnight lows remain in the 8–11°C range. Recent official briefings from September 11–12 consistently project an afternoon peak near 18°C, with ensemble guidance showing limited spread around this value and low odds of significant deviation from model consensus. Traders appear to weight the tight clustering of forecasts and the absence of disruptive factors such as strong frontal passages or anomalous blocking patterns, which supports the elevated probabilities for 16–18°C while assigning only marginal weight to outliers above 19°C or below 15°C. Updated model runs closer to the date will provide the next key data points for refining these market-implied odds.