Highest temperature in Tokyo on July 4?

Platform comparison

Market context

The highest temperature recorded at Tokyo Haneda Airport on 4 July 2026 is the real-world event this market resolves, and on Polymarket today the contract prices at 0% for any outcome above 26°C, implying traders believe a scorching heatwave is virtually impossible. This on-chain position, settled in USDC on Polygon via conditional tokens, reflects a stark disconnect from historical patterns where mid-to-late July routinely sees temperatures between 36°C and 40°C with humidity exceeding 95%, turning the city into a concrete jungle[1]. Recent data confirms Japan has shattered seventeen heatwave records since 1898, with temperatures soaring past 41°C in multiple cities, including a record-breaking 41.6°C in Tamba City[2][8].

Traders should monitor the Japan Meteorological Agency’s daily heatwave bulletins and the scheduled release of Wunderground’s hourly data for Haneda, as these are the primary dependencies for settlement[8]. A recent Reuters report highlighted that Japan hit its highest-ever temperature of 41.2°C on 30 July 2025, suggesting that extreme heat is not an anomaly but an escalating trend in the region[8]. The forecast for Haneda in July 2026 already indicates daily highs ranging from 76°F to 91°F (approximately 24°C to 33°C), which contradicts the market’s current 0% probability for higher ranges[4]. If the agency issues a special heat alert or if real-time sensors record temperatures above 35°C before noon, the market’s pricing will likely shift dramatically to reflect the on-chain reality of a potential heat event.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Polymarket Scam?, which mirrors the Polymarket order book directly.

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 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 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.