Highest temperature in Tokyo on August 1?

Platform comparison

Market context

Tokyo Haneda Airport’s highest temperature for 1 August will be set by the day’s actual observed peak, and the market is currently pricing **0% YES**, which is far below the normal August heat profile for Tokyo. AccuWeather’s August outlook shows Tokyo daily highs in a broad **82°F to 90°F** range, while travel and climate references put August as the city’s hottest month, with average highs around **31–33°C** and frequent afternoon peaks above **33°C**.[1][3][13][15]

That makes the contract’s current price look notably conservative versus the historical backdrop. Tokyo’s long-run August monthly high average sits around **34.6°C** in one climate-history dataset, and the city’s all-time August extreme in that record reached **37.3°C**, showing that a station high well above the low-30s remains plausible on a hot day.[2] By comparison, recent 1 August weather in Tokyo has often started in the upper 20s Celsius and climbed later in the day, which matters because the settlement window runs until **12:00 UTC** and still captures the main daytime warming period at Haneda.[5]

For traders, the key catalysts are the morning and midday observations at Tokyo Haneda, plus any shift in cloud cover, sea breeze, or rain affecting the airport itself rather than central Tokyo. AccuWeather’s near-term August forecast already implies a warm baseline, but the final outcome depends on the actual airport reading on the day, not citywide averages or other stations.[1][14] On cross-platform odds, there is little evidence here of a meaningful sportsbook-style line to anchor against, so the main comparison is between the prediction market’s flat **0%** and the climatological expectation that Haneda can still post a materially higher daytime maximum than current pricing suggests.[1][2][15]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Tokyo on August 1? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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

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.

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