**Trader consensus on 19°C as Warsaw’s daily maximum reflects direct observational data from local weather stations showing afternoon peaks of 19–20°C under stable high-pressure conditions.** Multiple forecast models, including GFS runs, aligned on this range with light southwesterly winds, minimal cloud cover midday, and no significant advection of warmer air. Historical September climatology for the city places average highs near 19–20°C, providing further context for the tight market pricing. Late-day readings and post-sunset cooling have now locked in the outcome. Only an undetected station calibration issue or atypical microclimate variation at the official recording site could alter the final verified maximum.