Current observational data from Tokyo-area stations, including reports near 25°C amid widespread rain and overcast skies under a frontal system, combined with GFS model consensus, have driven near-certain market-implied odds for a 26°C daily maximum. This aligns with late-September climatology, where highs typically range 24–26°C as seasonal cooling sets in, with high humidity and light southwesterly winds limiting further warming. Official JMA verification of the exact peak remains the key resolution threshold. A late-day surge above 27°C from unexpected clearing or measurement discrepancies at the primary station could theoretically alter outcomes, though current conditions and model runs make such shifts improbable.