Highest temperature in Tokyo on June 30?

Platform comparison

Market context

The underlying event is the highest temperature recorded at Tokyo Haneda Airport on 30 June 2026, a date that marks the official start of Japan’s hot season. Historical data shows June highs in Tokyo typically range between 24°C and 32°C, with record extremes reaching 36.4°C in recent years during intense heatwaves. The current crowd-implied probability of 0% for any specific high-temperature range suggests the market views the outcome as too uncertain or the range definitions as misaligned with likely outcomes, despite June 30 being climatologically warm.

Traders should monitor daily weather bulletins from the Japan Meteorological Agency and real-time updates from Wunderground, which serves as the resolution source. Recent news from Al Jazeera confirms Japan hit a national record of 41.2°C in July 2025 amid the hottest June on record, indicating that extreme heat is possible even in late June. With AccuWeather forecasting Haneda’s June 2026 highs between 25°C and 28°C, the divergence between sportsbook lines (which may offer tighter ranges) and the 0% prediction-market probability highlights a meaningful gap in how analysts interpret the risk of a record-breaking day versus typical seasonal variability.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Tokyo on June 30? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Best Prediction Markets, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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.

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