**Persistent warm, moist air and widespread cloud cover with thunderstorms are keeping overnight lows elevated in Busan on August 28, 2026.** Forecasts from multiple sources (Met Office, Meteoprog, Yonhap, PredictWind) converge on a daily minimum of 25–27°C, driven by high dew points near 26–27°C that limit radiative cooling under overcast skies and light southerly winds. Heavy rain and thunderstorm activity—ongoing from prior days and expected to continue with 70–100% probability—further suppresses temperature drops through cloud insulation and reduced clear-sky heat loss. This setup explains the tight clustering of market-implied odds around 24–26°C (45–50% each), as small differences in model timing for any partial clearing, wind shifts, or precipitation intensity could tip the exact minimum by 1°C. Historical late-August averages are lower (~23–24°C), but the current moist, disturbed pattern raises the floor. Traders are monitoring the latest official updates from the Korea Meteorological Administration for any final-hour adjustments to the overnight low before resolution.