**Trader sentiment for Wellington’s July 6 high temperature centers on 12–13 °C because current forecast guidance and long-range outlooks cluster there.** July climatology for Wellington shows an average daytime maximum near 11–12 °C, with typical ranges of 10–14 °C under winter conditions. Multiple numerical weather prediction outputs and agency guidance issued in the past 48 hours place the most likely maximum between 12 °C and 13 °C, producing the tight 41.5 % / 33.5 % market split. Key differentiating factors include the strength and timing of an incoming southerly change. Stronger southerlies advect cooler maritime air and increase cloud cover and showers, capping the daily maximum near or below 12 °C. Weaker or delayed southerlies allow more northerly influence or clearer breaks, permitting brief warming to 13 °C. Model spread arises mainly from small differences in frontal timing and wind speed rather than large-scale pattern changes. Recent MetService updates highlight an unsettled regime with gusty winds and rain returning to the region, which historically suppresses daytime highs by 1–2 °C relative to clear-sky cases. Seasonal NIWA guidance reinforces near- or below-average temperatures for the period, keeping extremes below 11 °C or above 14 °C at low probability. Updated model runs and official briefings over the next 24–48 hours will likely narrow the 12–13 °C range as the synoptic details sharpen.