Highest temperature in Tokyo on July 4?

Platform comparison

Market context

The highest temperature recorded at Tokyo Haneda Airport on 4 July 2026 will determine the outcome of this prediction market, which currently prices the 27°C range as the frontrunner at 57% probability, while the 26°C range sits at 26% and all higher ranges, including 28°C and beyond, trail at less than 1% each[1]. This market resolves on the USDC-based conditional tokens platform running on Polygon, where traders buy shares in temperature brackets that settle to USDC if their range wins, with the settlement window closing at 12:00 UTC on 4 July 2026 once Wunderground publishes the first data point for that date[1].

Historical July weather in Tokyo consistently delivers extreme heat, with mid-to-late July routinely hitting 36°C to 40°C across the city and Osaka, often accompanied by humidity exceeding 95%[2]. Recent records underscore this trend: Japan logged two new national heat records in a single day in July 2025, with mercury soaring to 41.6°C and then 41.8°C, while Tokyo’s Ome City recorded 40.4°C on that same day[3][9]. Even Haneda’s July 2026 forecast shows daily highs between 76°F and 91°F (24°C to 33°C), suggesting that a 27°C peak is plausible but higher temperatures remain statistically likely given the season’s intensity[5].

Traders should monitor the Japan Meteorological Agency’s daily heat advisories and real-time temperature feeds from Haneda, as sudden shifts in cloud cover or sea breeze can alter peak readings within hours[3]. The agency recently confirmed Tamba City’s 41.2°C record as Japan’s highest-ever temperature, reinforcing that Tokyo can approach similar extremes under favourable conditions[8]. With peak heat typically occurring between 11:00 and 18:00, any unexpected cooling during this window could suppress the day’s maximum, but the prevailing climate pattern points toward sustained high temperatures that may push the outcome beyond the current 27°C consensus[2].

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 PolyGram, which mirrors the Polymarket order book directly.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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

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.

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 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.