Highest temperature in Tokyo on July 31?

Platform comparison

Market context

Polymarket is pricing this contract at **0% YES** today, so the on-chain market on Polygon is effectively assuming the day’s top temperature at Tokyo Haneda Airport will not land in the YES range. On Polymarket, buyers and sellers swap USDC-backed conditional tokens, so the live price reflects where traders think the settlement value will fall, not just whether Tokyo feels hot at street level.

For context, Tokyo’s late-July climatology is firmly warm to hot: July averages are around 84°F/29°C, with daily highs commonly in the low-to-mid 80s Fahrenheit and occasional stronger spikes closer to 90°F/32°C or above.[2][18] That makes the market sensitive to whether the airport station records a modestly warm afternoon or a sharper heat peak; Haneda can sit below headline city forecasts if coastal influence, cloud cover, or showers cap the maximum. Forecasts in the results are already split between roughly 84°F/29°C and 91°F/33°C for the day, showing why the final print still matters more than the broad summer norm.[2][7]

The main catalysts are the daytime forecast updates, any convective rain or thunderstorm development, and the exact timing of the maximum before the settlement window closes at 12:00 UTC, which is mid-afternoon in Tokyo. Japanese forecasters had warned of Tokyo reaching about 36°C on 31 July in one official update, but other services showed lower highs and heavy precipitation risk, so traders should watch for whether heat or cloud/rain wins out at Haneda.[6][3] Because the market resolves from Wunderground’s recorded daily high at Tokyo Haneda Airport Station, the relevant dependency is the airport observation itself rather than central Tokyo forecasts.[11]

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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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.

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