Recent ensemble forecasts from the Global Forecast System and European Centre for Medium-Range Weather Forecasts project Taipei’s May 18 daily maximum near 31–32 °C, reflecting a strengthening subtropical ridge that promotes subsidence, clear skies, and strong daytime heating over the northern Taiwan plain. This positions the 31 °C and 32 °C contracts as near-equals because small variations in afternoon sea-breeze timing or localized convective development can shift the peak by 1 °C either way. Mid-May climatology places the historical average high around 29 °C, so current guidance sits modestly above normal, yet the market’s tight clustering around 31–33 °C underscores genuine uncertainty in boundary-layer moisture and orographic effects from surrounding hills. Updated Central Weather Administration guidance and the 00 UTC model runs tomorrow morning represent the next key catalysts that could refine resolution probabilities.