Recent Met Office and model guidance indicate a mild air mass over southern England on August 16, with nighttime minima forecast near 16–17 °C under partly cloudy skies and light winds that limit radiative cooling. These conditions sit several degrees above the long-term August average low of roughly 13–14 °C, supporting the market’s heavy weighting toward 17 °C and 18 °C as the most probable overnight minimums. Ensemble spreads remain narrow, with only modest downside risk to 16 °C if clearer spells develop; warmer outcomes above 18 °C would require stronger southerly flow or increased cloud cover that is not currently favored. The primary catalyst remains the latest 00Z–12Z model runs showing stable high pressure and limited Atlantic influence through the overnight period.