Highest temperature in Tokyo on August 7?

Platform comparison

Market context

Tokyo’s daytime heat on 7 August will be set by whether the city gets a standard midsummer high or a sharper spike at Haneda Airport, which is the settlement reference point here. The current crowd price of **0% YES** looks far below the kind of outcome implied by both seasonal climatology and the live forecast market: Tokyo’s August average high is about **31°C**, with many summer days moving above **30°C**, while one prediction venue shows the contract clustered mainly around **33°C–34°C** rather than anywhere near the lower ranges needed for a NO-dominant read.[2][4][3]

Historically, Tokyo’s August heat makes a single-digit Celsius outcome improbable, and even a modestly cooler-than-normal day still tends to sit in the low 30s. JMA’s August day-by-day data for Tokyo already shows highs of **35.6°C at Haneda** on 1 August and **33.0°C** on 2 August, reinforcing that the airport site can run hot even when the broader city is only near seasonal norms.[1] That makes the live market’s distribution more informative than the binary crowd figure: the prevailing consensus is not that Tokyo will stay cool, but that the likely peak is concentrated in the low-to-mid 30s.[3][2]

Traders should watch the Japan Meteorological Agency updates, the hourly forecast path, and any last-minute shifts in humidity, cloud cover, or sea-breeze flow that can move Haneda’s peak by a degree or two.[15][5] The main catalyst is timing: once morning heating is established, the highest temperature is often locked in by early afternoon, so revisions to the day’s forecast before then matter more than later changes.[4][15]

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

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.

UK Frequently Asked Questions

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.

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.

What are the best prediction markets for UK traders in 2026?

For UKGC-regulated markets: Betfair Exchange (sports, politics) and Smarkets (sports, politics, lower commission than Betfair). For broader global event prediction: Polymarket (deepest liquidity, 0% fee, USDC settlement). For US-regulated option: Kalshi (USD, limited UK payment options). Most serious UK traders use a combination of Betfair for regulated sports and Polymarket for broader markets.