**A cold front and wind shift to strong southerlies on September 10 are the dominant drivers of trader sentiment for Wellington’s daily minimum temperature.** As of September 9, northerly flow maintains milder conditions, but the front’s northward advance is expected to bring a sharp change to southerly winds, advecting cooler maritime polar air and increasing the chance of showers or rain. Official guidance from sources such as MetService, WeatherBug, and the NZ Met Office points to a daytime high near 13–14 °C followed by an overnight low in the 4–7 °C range, with the precise minimum highly sensitive to the front’s timing, wind strength, and cloud cover. **Model and observational uncertainty creates a broad probability distribution across the 3–10 °C bins.** Southerly flow can enhance radiative cooling under clearer breaks or limit it with persistent rain and mixing; Wellington’s coastal and hilly terrain adds local variability. The elevated 25 % market-implied probability on 3 °C or below reflects the potential for a stronger or earlier southerly surge, while the cluster of roughly equal odds (20–23.5 %) on 6–10 °C captures the more likely range under typical spring frontal passages. The near-zero odds on 13 °C or higher align with the expected cooling. Traders are therefore weighting the latest model runs and official briefings on the front’s arrival and intensity, which will determine whether the minimum settles in the lower or mid-single digits.