Highest temperature in Tokyo on June 30?

Platform comparison

Market context

The underlying real-world event is the highest temperature recorded at Tokyo Haneda Airport on 30 June 2026, measured in whole degrees Celsius. Polymarket prices this contract today with a 0% probability for the "YES" outcome, implying the crowd believes the temperature will not fall within the specific range defined by the market. This pricing reflects the on-chain mechanics of conditional tokens settled in USDC on the Polygon network, where liquidity providers have effectively wagered against the event occurring.

Historical data frames this near-zero probability with stark clarity. June in Tokyo has recently seen record-breaking heat, including a 2025 peak of 41.2°C and a 2024 record of 36.4°C, with the city logging ten consecutive days above 35°C in one sweltering summer [5][9][10]. However, the average high for Haneda in June sits around 27°C (80°F), and the hot season officially begins only on 29 June, suggesting that while extreme heat is possible, the specific range targeted by this market is statistically unlikely to be hit on this exact date [3][4].

Traders should monitor the official weather agency announcements and the Wunderground data feed as the primary catalysts, given that the market resolves only once the first data point for 30 June is published [1]. Recent news highlights Japan’s escalating climate crisis, with record June temperatures becoming a recurring trend that could push daily highs toward the 30°C threshold or higher [5]. The settlement window ends at 12:00 UTC on 30 June 2026, meaning any delay in data publication from the National Weather Service or Wunderground could impact the final resolution timing [2].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Tokyo on June 30? 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 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.

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.