Recent MetService forecasts for Wellington on September 13 indicate a high near 16°C under mainly fine conditions, with northwest winds shifting southerly and light variable breezes developing later, supporting modest daytime warming in early spring. International models align closely, projecting peak temperatures of 14–15°C amid partly cloudy skies and moderate humidity, consistent with seasonal norms for the region where ocean moderation and prevailing westerlies typically limit extremes. The strong market-implied probability for 15°C reflects this consensus from numerical weather prediction runs, with lower odds on 14°C or 16°C capturing minor ensemble spread from wind shifts or cloud cover. No significant atmospheric changes have altered the outlook in the past 24 hours, though final resolution depends on the precise maximum recorded at official stations.