Highest temperature in Tokyo on August 2?

Platform comparison

Market context

Polymarket is pricing this contract at **0% YES** even though the real-world question is whether Tokyo Haneda Airport Station will log its highest temperature in the market’s settlement range on 2 August 2026, with the result taken from Wunderground’s daily history page for RJTT and settled in conditional tokens on Polygon against USDC. On a hands-on basis, that means the live market is effectively saying traders see no meaningful chance of an extreme late-day spike above the relevant band before the 12:00 UTC cutoff.

That pricing sits against a backdrop of Tokyo’s August heat profile, which is normally hot rather than record-breaking. Historical and climate summaries put typical August highs around 31–34.6°C, with long-run records in the high 30s and a Tokyo record high of 39°C in 1994, while recent summers have repeatedly produced severe heat elsewhere in Japan and several Tokyo heat alerts. The important point for this market is that the contract is not asking whether Tokyo is “hot” in general, but whether the *single highest observation* for the station on the day lands inside the market’s chosen Celsius bucket. [1][2][3]

For traders, the main catalysts are the same-day weather evolution at Haneda: cloud cover, rain bands, sea-breeze effects, and whether afternoon heating peaks before the settlement window closes. Short-term forecast services for Tokyo point to early-August highs in the low 30s °C, with August averages near 31°C to 34°C, which is consistent with a hot day but not necessarily a record-setting one. Because settlement uses the station’s Wunderground reading rather than a citywide average, the relevant watch items are the hourly forecast, any sudden convective rain, and whether the maximum is logged before noon UTC. [4][6][9][17]

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 Polymarket Alternative UK. 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.

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