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 Station on 30 June 2026, measured in whole degrees Celsius. Polymarket prices the YES contract for this specific temperature range at 0% today, implying the market believes the outcome is impossible under current conditions. This on-chain pricing, settled in USDC on the Polygon network via conditional tokens, reflects a consensus that the temperature will not fall within the defined bracket, regardless of the actual weather.

Historical data frames this near-zero probability sharply. June in Haneda typically sees daily highs between 75°F and 83°F (24°C–28°C), with the average high at 80°F (27°C) [3]. However, Japan has recorded extreme heat recently, including a national peak of 41.2°C in July 2025 after the hottest June on record [5]. Tokyo also logged 10 consecutive days above 35°C in August 2024 [10]. Given that 30 June marks the start of the hot season, with average highs above 79°F from this date onward [4], the 0% price appears to ignore the potential for record-breaking spikes, suggesting the bracket may be set unrealistically low.

Traders should monitor the Japan Meteorological Agency’s daily heatwave advisories and the Wunderground resolution source for real-time updates on 30 June [2]. The primary catalyst is the official high-temperature reading published at 12:00 UTC, which will determine resolution once the first data point for the following day is released [1]. Any announcement of an intense heatwave or a temperature exceeding 35°C would directly challenge the current pricing, as recent records show Tokyo can sustain extreme heat for extended periods [8]. The market’s dependency on Wunderground’s whole-degree precision means even a 0.5°C variance could shift the outcome, making live tracking essential.

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

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.

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