**Trader sentiment clusters tightly around 26–28°C for Seoul’s July 3 maximum, reflecting near-term forecast uncertainty amid typical early-July conditions.** July marks the onset of South Korea’s East Asian summer monsoon (Jangma), bringing warm, moist southerly flow, high humidity (often 70–85%), and frequent afternoon convective showers or thunderstorms that can cap daytime heating through cloud cover and evaporative cooling. AccuWeather’s July 2026 outlook shows typical Seoul highs of 27–32°C (81–90°F), consistent with climatological norms of upper-20s maxima. The narrow spread among leading outcomes arises because short-range models (from the Korea Meteorological Administration and global ensembles) differ on the timing and extent of cloud build-up or isolated showers on July 3, which can shift the peak by 1–2°C. Urban heat-island effects in Seoul amplify baseline readings, while weak steering winds and high moisture content reduce large day-to-day swings. Lower-probability 31°C+ outcomes would require clearer skies and stronger subsidence, whereas cooler results hinge on earlier or heavier precipitation. Updated model runs and official KMA briefings over the next 48 hours remain the key catalysts for any market shifts.