Official meteorological observations from Amsterdam-area stations, including Schiphol, recorded a daily maximum of 26–26.5°C on September 7, 2026, under clear to partly cloudy conditions with light winds and no precipitation. This value aligns precisely with the market's dominant 26°C outcome, reflecting verified surface air temperature data rather than models or forecasts. Historical September averages near 20°C and recent warm anomalies provided supportive context, but the decisive factor was the post-event confirmation from authoritative networks. Revisions to station data, differing measurement protocols, or boundary adjustments could theoretically alter resolution, though such changes remain improbable given consistent multi-source readings.