Highest temperature in Tokyo on August 12?

Platform comparison

Market context

The market is pricing the peak temperature at Tokyo Haneda Airport on 12 August 2026 at 0% probability for any given range, suggesting the crowd expects an outcome outside the listed brackets or has not yet engaged with the question. August in Tokyo typically sees daily highs between 32–35°C, with extreme heat occasionally pushing toward 37–38°C during particularly intense heat waves. The settlement will draw from Weather Underground's Daily Observations table at Haneda, the primary meteorological station for the metropolitan area, rather than summary figures that sometimes diverge from raw observational data.

Historical August temperatures at Haneda show the city rarely exceeds 36°C on any single day, though the 2010 heat wave produced readings near 39°C across Japan. The 0% crowd probability likely reflects either low trading volume or uncertainty about which temperature bracket the market offers; traders should verify the specific ranges available before positioning. Recent summers have tracked within normal bounds, with 2023 and 2024 August peaks at Haneda falling in the 33–35°C band, establishing a baseline for typical conditions two years hence.

The key variable is whether a Pacific high-pressure system stalls over the Kanto region during early-to-mid August 2026. Japan Meteorological Agency forecasts, typically issued 10–14 days ahead, will signal whether anomalous heat is developing. Any tropical cyclone activity in late July could suppress August temperatures, whilst persistent anticyclonic conditions would favour above-normal readings. Traders should monitor early August 2026 weather patterns and seasonal outlooks from late July onwards.

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.