Current forecasts for Cape Town on September 13 indicate an overnight minimum near 15°C under mostly cloudy skies with light showers and light southeasterly winds, consistent with spring transitional patterns where Atlantic moderation limits cooling. Historical September lows average around 10–11°C, but recent model runs show reduced radiative cooling from persistent cloud cover and higher dew points near 14°C, supporting trader emphasis on the 15°C outcome. Key differentiating factors include variable wind speeds that suppress temperature drops, timing of any clearing that could allow brief radiative losses toward 12–14°C, and potential model spread on precipitation intensity, which explains the near-even market probabilities across the 11–15°C and higher ranges without a dominant consensus. Updated official guidance from regional monitoring is expected overnight.