Recent MetService and Met Office guidance for Wellington on August 11 points to a daily maximum near 12–13°C under northerly flow, with a few early showers giving way to increasing cloud. This narrow spread, reflected in the near-even 12°C and 13°C market shares, stems from small differences in model timing of a possible frontal passage and wind strength across Cook Strait, which can rapidly alter boundary-layer temperatures. Northerlies typically advect milder maritime air, yet any increase in southerly components or persistent low cloud would cap the peak closer to 12°C, consistent with the city’s August climatology of roughly 13°C. Updated runs and local observations in the next 24–48 hours will clarify whether conditions favor the upper or lower end of that range.