Ensemble forecasts from MetService and international models show the overnight minimum in Wellington hovering near 9–10 °C, producing the tightest market clustering at those levels. Springtime radiative cooling under variable cloud cover, combined with moderate southerly winds and a weak high-pressure ridge, limits how low temperatures can fall while preventing sharp drops below 7 °C. Key uncertainties include the exact timing of any passing front and local topographic effects around the harbor that can alter boundary-layer mixing. The next model update cycle and real-time observations from the airport station will refine these probabilities before midnight on October 15.