Highest temperature in Tokyo on July 23?

Platform comparison

Market context

Polymarket is pricing this Tokyo Haneda Airport temperature contract with **35°C** as the clear leader at **97%**, while **36°C** is just **2%** and the rest of the ladder is effectively ignored by the market.[1] Because settlement is in USDC on Polygon through conditional tokens, the practical question for a holder is not whether Tokyo will be warm in general, but whether the day’s official Wunderground high for RJTT lands in the 35°C bucket by the resolution cut-off.[1]

That pricing sits neatly alongside the July climate pattern in Tokyo. Historical travel-weather references describe July as typically hot and very humid, with average highs around **29–33°C** and heat-wave peaks reaching **38–39°C**, so a 35°C reading is well within a plausible midsummer range rather than an extreme tail event.[2][3] In prediction-market terms, the current 0% YES crowd view looks less like a claim of impossibility and more like a sign that traders expect the final airport maximum to finish in the market’s favoured 35°C band rather than push into the next bracket.[1]

For traders, the main catalysts are the morning-to-afternoon evolution of Tokyo’s heat, cloud cover, sea breeze, and any convective rain that caps the daytime high before the Wunderground daily maximum is locked in for Haneda.[1] The key dependency is the airport station reading itself, not city-centre temperatures, so short-lived spikes or runway-area conditions matter more than broader Tokyo headlines. The market settles from the Wunderground history page for Tokyo Haneda Airport Station, and once the day is over the recorded highest temperature on that source determines which conditional token pays out.[1]

Sources: 1 · 2 · 3

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.