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. On Polymarket today, the contract trades with a 0% implied probability for the “YES” outcome, reflecting the crowd’s certainty that the temperature will not fall within the specified range. This pricing is driven by on-chain mechanics using USDC on the Polygon network, where conditional tokens lock liquidity based on historical weather patterns rather than speculative forecasts.

Historically, late June in Tokyo marks the onset of the hot season, with average daily highs exceeding 79°F (26°C) and frequent peaks reaching 35°C or more. In 2025, Japan recorded its highest temperature ever at 41.2°C, following the hottest June in 147 years, when Tokyo hit 36.4°C [5][9]. These precedents frame the current 0% probability as a rational assessment: the specified range is likely too narrow to capture typical late-June extremes, which often exceed 30°C.

Traders should monitor the Japan Meteorological Agency’s weekly heatwave advisories and Wunderground’s real-time updates for Haneda, as sudden shifts in cloud cover or wind patterns can alter peak temperatures. A recent report from The Straits Times noted Tokyo logged a record 10 consecutive days above 35°C in August 2024, underscoring the volatility of summer heat in the region [10]. The settlement window ends 2026-06-30T12:00:00Z, with resolution sourced exclusively from Wunderground’s highest daily reading for Haneda.

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

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

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

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.