Highest temperature in Tokyo on August 5?

Platform comparison

Market context

The contract turns on the *day’s peak temperature at Tokyo Haneda Airport*, and the live pricing is strikingly conservative at 0% YES, implying the market is effectively treating a qualifying high as very unlikely. That is notably below the broader weather picture: AccuWeather’s August outlook for Tokyo shows daily highs mostly in the low-to-upper 30s °C, with the month’s forecast range extending to 90°F (about 32°C), while timeanddate’s hourly forecast for 5 August already has Tokyo around 88°F (31°C) by late morning and early afternoon, with rain chances listed at 0%.[1][2]

Historically, Tokyo in August is a heat-prone market rather than a stable cool-weather one. Trip.com’s Japan August guide puts Tokyo’s average maximum at about 31°C and average minimum at 24°C, while JMA station data for Tokyo on 1–2 August 2026 already shows maxima of 36.5°C and 35.3°C at the central Tokyo observatory, with Haneda also printing 35.6°C and 33.0°C on those dates.[7][10][14] Against that backdrop, a 0% YES implies either the contract is being priced as an outlier outcome or traders are anchoring to the specific settlement source and its range bands rather than the city-wide heat profile; that gap is the main cross-platform divergence to watch versus broader weather forecasters, which are materially higher than the market.

For today’s catalysts, the key variables are the intraday temperature curve, cloud cover, and any late-afternoon sea-breeze or rain interference that caps the maximum before the settlement window closes at 12:00 UTC, which is 21:00 local time. Timeanddate’s forecast already points to overcast conditions but no precipitation, while JMA’s official forecast page and daily observations will be the most relevant live checks for whether Haneda is running hot enough to land in the target range.[2][16] In practice, prediction-market repricing usually follows the first reliable morning highs and any midday update from the official or airport-adjacent station rather than the broader city forecast, so any divergence between Haneda, central Tokyo, and sportsbook-style weather lines will matter most as the day progresses.[10][14]

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.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Kalshi vs Polymarket. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi vs Polymarket 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.