Highest temperature in Tokyo on July 4?

Platform comparison

Market context

On 4 July 2026, traders are betting on the peak temperature recorded at Tokyo Haneda Airport, with the crowd-implied probability for any outcome currently sitting at 0% YES despite active markets elsewhere suggesting a 57% chance of 27°C as the frontrunner. This stark divergence between prediction-market silence and Polymarket’s leading odds highlights a critical disconnect in how different platforms interpret the same weather contract, with Lines.com assigning only a 35% probability to 26°C while sportsbook lines remain virtually non-existent for such a specific meteorological snapshot.

Historical data frames this probability cautiously, as mid-to-late July in Tokyo routinely sees temperatures soaring to 36–40°C with humidity exceeding 95%, turning the city into a concrete jungle where peak heat lingers from 11 AM to 6 PM. Recent records reinforce this volatility, with Japan logging two new heat peaks in a single day at 41.6°C and 41.8°C, and the nation’s highest-ever temperature reaching 41.2°C in Tamba City just last year, suggesting that a 27°C cap is unusually conservative for this period.

Traders must monitor the Japan Meteorological Agency’s daily forecasts and any emerging heatwave advisories, as sudden shifts in cloud cover or sea breeze patterns could drastically alter the day’s maximum reading. A recent Reuters report on Japan’s record-breaking 41.2°C event underscores the need to watch for official temperature updates from the agency, which often release hourly data that can confirm whether Haneda will align with the broader regional heat surge or remain cooler due to coastal influences.

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Methodology

This page reviews Highest temperature in Tokyo on July 4? 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 PolyGram, which mirrors the Polymarket order book at 0% fees.

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

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 PolyGram 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.