Official meteorological observations from Paris-area stations recorded a daily maximum of 24°C on September 24, 2026, aligning precisely with the market's 100% implied probability for that outcome. This consensus rests on verified ground measurements reported by agencies such as Météo-France, which showed afternoon peaks near 23.7–24°C under partly cloudy conditions with light winds, consistent with model guidance and slightly above the September climatological average high of about 20–21°C. Traders' strong positioning reflects the low uncertainty inherent in post-event data verification, where resolution hinges on standardized maximum temperature readings rather than forecasts. Only rare factors like station-specific anomalies, reanalysis revisions, or differing measurement protocols could theoretically alter the recorded value, though such adjustments are uncommon once initial reports are confirmed.