Highest temperature in Tokyo on August 1?

Platform comparison

Market context

Tokyo Haneda Airport’s daily maximum on 1 August will be set by the hottest reading recorded there during the full settlement window, so late-morning and early-afternoon heating matters most for this market. August is Tokyo’s hottest month on average, with typical highs around 31°C and frequent days above 33°C, while historical records in Tokyo show the city can still spike far higher when synoptic heat builds over the Kanto plain.[11][12][2]

The 0% crowd-implied price suggests the market is currently treating a qualifying outcome as effectively impossible, but that is usually a poor anchor for a weather contract with a same-day resolution source. For a programmatic approach, the relevant inputs are the airport’s observed hourly trend, short-term forecast updates, and whether the day begins cool enough to cap the afternoon peak; Tokyo’s August climatology and past daily histories show a wide enough spread that a single hot afternoon can move the settlement band quickly.[4][10][12]

The main catalysts are the day’s official temperature observations at Haneda and any fresh forecast revisions that point to clearer skies, weaker wind, or stronger surface heating. Traders using conditional orders or automated repricing should watch the Japan Meteorological Agency-style hourly evolution indirectly through the Wunderground history page the market uses for settlement, because a small change in the daytime high can flip which temperature range is most likely once the afternoon maximum is established.[10][4]

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

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

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 Fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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