Highest temperature in Tokyo on July 23?

Platform comparison

Market context

Tokyo Haneda Airport’s highest temperature will be set by the afternoon heat and any shower or thunderstorm activity, not by the early-morning readings already on the board. At the time of writing, prediction-market pricing at 0% YES implies traders see little or no chance of an outcome in the market’s target band, while the weather platforms point to a much hotter day: one forecast shows a morning around 32°C, rising to 35°C in the afternoon before cooling later, and another warns of scattered showers and thunderstorms after a partial-cloud start.[1][2]

The historical frame is straightforward: late July in Tokyo is typically a hot, humid stretch, so maximums in the low-to-mid 30s Celsius are normal rather than exceptional.[4] That means the market is mainly about whether cloud cover, rain-cooled air, or thunderstorm timing trims the peak below the upper forecast range. Compared with sportsbook-style weather lines, which usually price the most likely daytime high rather than the exact airport station reading, the current 0% YES looks notably conservative against the available forecasts, while analyst-style consensus from the weather services is clustered around a mid-30s maximum.[1][2][3]

The main catalysts are the day’s convective timing and any update to the airport-specific history feed used for settlement. If showers arrive early enough, they can cap the station high below the broader Tokyo forecast; if they hold off until later, the airport can still print its maximum before the rain cools things down.[1][2] Traders should watch the live Wunderground station page, because settlement depends on the highest observed reading at Tokyo Haneda Airport Station on the day, not on citywide averages or the afternoon “feels like” temperature.[1]

Sources: 1 · 2 · 3 · 4

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

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.