**Trader sentiment for Wellington’s June 15 daily maximum temperature remains tightly balanced between 16 °C (40.5 %) and 17 °C (48.5 %), reflecting model consensus around a modest northerly warm-up followed by an evening southerly change.** Official MetService guidance issued in mid-June projects a 16 °C high under initially northwesterly flow that could briefly advect milder air, with showers turning to persistent rain as winds shift southwesterly later in the day. Other guidance (UK Met Office, Weather25) centers on 15 °C, consistent with June climatology of 12–13 °C average highs and the NIWA seasonal outlook for near-average temperatures. The narrow 1 °C spread between the leading outcomes stems from classic forecast sensitivities in Wellington: the exact timing of the frontal passage, the degree of daytime insolation before cloud increases, and small differences in boundary-layer mixing under gusty winds. Minor model-to-model or run-to-run variations in peak temperature or the strength of the northerly component can easily shift the realized maximum across the 16–17 °C threshold, which is why both outcomes command substantial market-implied probability while higher or lower values remain marginal. No major anomalous developments have altered the pattern in the past 48 hours; the market simply prices the residual scientific uncertainty inherent in short-range numerical weather prediction for a topographically complex coastal site.