Highest temperature in Tokyo on August 11?

Platform comparison

Market context

On 11 August 2026, Tokyo's highest temperature will be measured at Haneda Airport Station and recorded in Weather Underground's Daily Observations table. The crowd currently assigns zero probability to any outcome materialising, suggesting either extreme confidence in a specific range or genuine uncertainty about which threshold will be breached. August in Tokyo typically sees daily highs between 32–36°C, with occasional peaks above 37°C during heat waves, making the full range of possible outcomes plausible within normal seasonal variation.

Historical August data from Tokyo Haneda shows temperatures have exceeded 37°C in roughly 30–40% of years over the past two decades, whilst readings above 39°C occur in perhaps 10–15% of August days. The 0% crowd probability indicates the market may be waiting for clearer atmospheric signals before committing capital, or traders are hedging against model uncertainty given the two-year forecast horizon. Japan's Meteorological Agency will publish seasonal outlooks in coming months; any signal of an exceptionally warm summer pattern could shift consensus sharply toward higher temperature ranges.

The resolution hinges entirely on Wunderground's Daily Observations table at Haneda, not the summary high-low display, creating a technical dependency worth monitoring. Traders should track El Niño conditions, Pacific sea-surface temperatures, and any official summer forecasts from JMA, as these will inform whether August 2026 tracks toward typical or anomalous heat. The current flat market likely reflects genuine forecast difficulty rather than settled conviction.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Who Will Win 2026 trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.