Highest temperature in Seoul on July 8?

Platform comparison

Market context

On 8 July 2026, Seoul will experience its peak daily heat, with the Incheon International Airport station recording the highest temperature for the day. This single metric determines the outcome of a prediction market where the crowd currently assigns zero per cent probability to the “YES” outcome, implying near-certainty that the temperature will fall outside the specified range.

Historically, early July in Seoul has produced record extremes, including a 37.8°C peak on 8 July in a prior year—the highest ever recorded between 1 and 10 July since records began[1]. Typical July averages hover near 30°C, but humidity often pushes the felt temperature above 34°C, while the monsoon season (late June to mid-July) brings frequent, heavy rain that can suppress daytime highs[2][3]. The zero per cent implied probability suggests traders believe this year’s conditions will not replicate that record, likely due to ongoing rainfall or cloud cover expected during the monsoon window[2][4].

Traders should monitor real-time updates from the Korea Meteorological Administration for precipitation intensity and cloud cover, as these directly influence peak temperatures[4]. A recent forecast indicates 60% probability of rain with slight intensity and a felt temperature of 29°C, which would keep highs well below the record threshold[4]. Any sudden shift to clear skies before 3:00 pm local time could alter the outcome, but current data points to continued monsoon influence suppressing extreme heat[2]. Compare this weather-driven divergence against sportsbook lines that may overstate heat risk based on seasonal averages rather than live monsoon conditions.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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 Best Prediction Markets UK. 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.

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.

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.