Highest temperature in Tokyo on June 30?

Platform comparison

Market context

The underlying event is the peak daytime temperature recorded at Tokyo Haneda Airport on 30 June 2026, a date that historically marks the onset of Japan’s intense summer heat. Current crowd-implied probability sits at 0% for the "YES" outcome, suggesting the market expects the temperature to fall outside the specific range being traded. This aligns with historical patterns where late June in Tokyo frequently sees highs between 24°C and 32°C, though extreme outliers have occurred. For instance, Japan recorded a national high of 41.2°C in Tamba city during the hottest June on record in 2025, while Tokyo itself hit 41.8°C in a separate record heatwave, demonstrating that temperatures can surge well beyond typical averages under specific climatic conditions[2][6].

A programmatic trader approaching this market would monitor real-time feeds from Wunderground and the National Weather Service for deviations from the AccuWeather forecast, which projects daily highs of 75°F to 83°F (approximately 24°C to 28°C) for Haneda in June 2026[4]. Key catalysts include sudden shifts in the Pacific high-pressure system or the arrival of a typhoon, both of which can drastically alter temperature trajectories. Recent news from Anadolu Agency highlights Tokyo’s record June temperatures in 147 years, with peaks reaching 36.4°C, indicating that even minor atmospheric anomalies can trigger significant spikes[9]. Traders should also watch for government heat advisories, which often precede record-breaking days, as these signals can be integrated into conditional order algorithms to adjust exposure dynamically[2]. The settlement window closes at 12:00 UTC on 30 June 2026, requiring precise timing for data ingestion and position management.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Tokyo on June 30? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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

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.

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.