Trader consensus on Polymarket closely splits between 20°C (32%) and 21°C (30.5%) for Moscow's highest temperature on May 15, reflecting ensemble forecast spread from ECMWF, GFS, and Russian Hydrometeorological Center models projecting daytime highs of 20–23°C under cloudy skies with scattered showers and possible thunderstorms. This positioning stems from a recent warming trend—May 13 peaked at 22°C, with May 14 forecasts reaching 21–23°C—fueled by southerly winds of 6–11 m/s advecting milder air masses amid a transitioning upper-level pattern. Differentiating factors include variable cloud cover limiting insolation for the diurnal maximum (typically 2–5 p.m. local time) and localized convective activity potentially capping peaks at 20°C in drier model runs versus 21°C+ with partial clearing. New hourly observations and evening forecast updates from official stations will sharpen resolution before midnight May 15.