Highest temperature in Tokyo on August 8?

Platform comparison

Market context

Tokyo’s highest temperature is expected to land in the low-to-mid 30s Celsius, which is the key band for this contract because the market resolves to the range containing the top reading at Haneda Airport rather than the summary high. Forecasts for 8 August are clustered around 33–35°C, with AccuWeather showing 92–94°F and Yahoo Japan putting the daytime peak at 35°C; that makes a 0% Yes price look notably detached from the weather board consensus, even before allowing for airport-level variability.[2][3][9][11]

The historical framing is straightforward: Tokyo in August is typically the hottest part of the year, and daytime highs commonly clear 30°C, with mid-30s readings not unusual in modern August heat.[12][19] For a contract like this, the relevant comparison is not the citywide average but the specific station observation at Haneda, where sea-breeze effects, cloud timing, or a late-afternoon shower can shave a degree or two off the headline forecast. Traders should therefore watch the 1-hourly forecast updates and any short-term thunderstorm or rain timing changes, because the spread between 33°C and 35°C is enough to move the settlement bucket even if the broader “hot day” narrative does not change.[3][7][8]

On cross-platform pricing, the visible odds gap is unusual: sportsbook-style weather views and mainstream forecast sites are effectively pricing a hot Tokyo day, while the prediction market is at zero. That divergence usually signals either stale market pricing or an assumption that the station reading will undershoot the city forecast, but the latter would need a meaningful cooling surprise to be right. With the settlement source tied to Weather Underground’s Daily Observations table, the final check is the actual Haneda observation trail rather than any day-high summary, so the most important dependency is the intraday station record itself.[8]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Tokyo on August 8? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

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.

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 PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.