**Trader sentiment for Milan's August 21 daily minimum temperature reflects uncertainty between storm-driven moderation and potential radiational cooling overnight.** Official forecasts from sources like timeanddate, BBC Weather, and AccuWeather point to a high near 23–26°C under strong thunderstorms and overcast skies, with lows projected in the 15–20°C range (roughly 59–68°F). This follows a mid-August heat pattern across northern Italy that produced highs of 31°C or more earlier in the month, now giving way to a cooler, unsettled pattern as a frontal system moves through the Po Valley. Key scientific factors include cloud cover and precipitation, which trap outgoing longwave radiation and limit nighttime cooling compared to clear-sky conditions that allow efficient surface heat loss. Light easterly winds and high humidity from thunderstorms further reduce the diurnal temperature range by enhancing mixing and latent heat effects. Historical August averages for Milan show overnight lows typically declining from ~19°C early in the month toward 16–17°C later, providing context for why probabilities cluster around 13–18°C bins rather than warmer outcomes. The closely matched leading probabilities (43% for 13°C or below, 37% for 18°C) capture model spread on whether storms clear sufficiently for enhanced cooling or maintain elevated minima through persistent cloudiness and moisture. Upcoming hourly observations and updated numerical weather prediction runs from agencies like the Italian Meteorological Service will refine this picture as the day progresses.