Real-time observations from Wellington weather stations, including METAR reports showing a peak of 14°C midday under clear to partly cloudy skies with northerly winds, have driven the market's near-certain consensus on that exact high for September 9. Spring climatology in the region typically features variable highs around 13–15°C, and model guidance plus on-site measurements aligned closely without evidence of warmer pockets or measurement revisions. The dominant positioning reflects aggregated trader assessment of authoritative data streams, with only narrow uncertainty from potential late-day adjustments or station-specific differences that have not materialized.