Forecast models point to an overnight low in Wellington on August 30 most likely between 9–11 °C, driven by clear to mostly clear skies that permit strong radiative cooling after sunset, combined with moderate northwesterly winds that limit extreme drops through mixing of the boundary layer. Recent days have shown similar patterns, with minimums fluctuating around the August climatological average of roughly 10 °C at Wellington Airport. Ensemble guidance and local MetService outlooks converge on this narrow range, though small differences in cloud cover timing or wind strength create the tight spread among the leading market outcomes at 9 °C, 10 °C, and 11 °C. Traders are weighting the most probable single-degree bins while acknowledging typical forecast uncertainty of 1–2 °C within 24 hours of the event.