Highest temperature in Tokyo on July 9?

Platform comparison

Market context

Tokyo’s official daily high temperature on 9 July 2026 will be measured at the Tokyo Haneda Airport Station, with the market resolving to the exact degree band that contains this peak reading. The current crowd-implied probability for the 29°C outcome sits at 0% on one platform, yet cross-platform odds reveal a stark divergence: Lines.com prices the same 29°C band at 0.32, implying a 31.5% chance, while Bitget shows significant volume concentrated on 31°C and 30°C bands. This fragmentation suggests forecast models are converging on 29°C as the plurality favourite, though it remains a minority outcome in an eleven-way split where ten other bands absorb the remaining probability.

Historical July highs at Haneda typically range between 27°C and 32°C, with the Met Office forecasting a maximum of 31°C for the coming week, aligning with the 31°C volume seen on Bitget. The Japan Meteorological Agency recently recorded a national high of 41.2°C in Tamba city, indicating a broader warming trend that could push Haneda’s peak above the 29°C threshold. Traders should monitor the next JMA forecast publication, as price can move sharply before the 12:00 UTC resolution window, and watch for real-time Wunderground updates which serve as the official settlement source. The divergence between the 0% implied probability and the 31.5% Lines.com price highlights a critical arbitrage opportunity for those tracking cross-platform consensus.

Sources: 1 · 2 · 3 · 4 · 5

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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 fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.