**Forecast models indicate a daily minimum temperature in Wellington on August 28, 2026, most likely between 9–12°C, consistent with the closely matched market-implied odds favoring 12°C (48.5%), 13°C (42.5%), and 11°C (32.5%).** Short-range guidance from sources including MetService-linked outlooks, WeatherBug, and Ventusky shows overnight lows near 9–11°C under a mix of partly cloudy conditions and moderate winds. A frontal passage and shifting wind patterns—northerlies giving way to southerlies—introduce variability through advection of cooler maritime air and potential radiative cooling under clearer spells. Historical climatology places the typical late-August minimum near 8–9°C (47°F), so current runs sit slightly above average due to milder northerly flow earlier in the period. Uncertainty in exact minimum stems from model differences in timing of cloud cover, wind speed (which limits nocturnal cooling), and any showers, which can moderate temperature drops. Traders price the 11–13°C cluster highest because ensemble guidance clusters there, while lower outcomes (9–10°C) retain meaningful probability if stronger southerly winds or clearer skies develop. New model runs and official MetService updates over the next 24–48 hours will refine these probabilities ahead of the 28th.