Official meteorological observations from Météo-France for May 16 recorded a daily maximum of 16°C in Paris, establishing the market-implied odds at essentially 100% for that exact threshold. This reading aligns with surface station data under stable spring atmospheric conditions, where limited solar heating and moderate northerly flow kept temperatures below the mid-May climatological average of roughly 18–20°C. Forecast models issued in the preceding 48 hours had converged on this range, with minimal spread among ensemble runs. Minor revisions remain possible only if post-processing adjustments alter the official high by a fraction of a degree, though historical verification timelines indicate such changes are rare once preliminary data are released.