Pakistan Meteorological Department forecasts maintain a heatwave over Karachi through May 19, driven by continental air advection and upper-level subsidence that promote strong daytime solar heating and minimal cloud cover, positioning the 37°C-or-higher bracket as the market leader. Ensemble models cluster around 35–37°C peaks, with sea-breeze onset from the Arabian Sea and 40–70 percent daytime humidity creating 1–2°C variability that keeps the 35°C and 36°C outcomes closely competitive. Historical May baselines for Karachi show typical highs of 34–38°C before monsoon suppression, underscoring how current subsidence strength and breeze timing will determine the official high recorded by the department’s surface stations.