**Wellington's winter temperature variability centers on southerly airflow strength and cloud cover as the key drivers for July 8 maximums.** Official climatology places the July average high near 12°C, with NIWA's May–July 2026 outlook assigning roughly equal chances of near-average or below-average conditions for the Wellington region amid typical Southern Ocean influences. Short-range guidance from MetService currently shows highs around 12°C under mostly cloudy skies and easing but persistent southerlies, which advect cooler maritime air and limit daytime warming. Minor model differences in front timing or wind backing could easily tip the daily peak between 11–13°C, explaining why the market assigns nearly equal implied probabilities to 12°C (42.5%) and 13°C (39.5%). Clearer skies or a temporary northerly component would favor the upper end of that narrow range, while stronger onshore flow or showers would cap readings closer to 11°C. Updated NWP runs and the next MetService briefing remain the primary near-term catalysts for any shift in trader positioning.