Highest temperature in Seoul on June 30?

Platform comparison

Market context

The underlying real-world event is the highest temperature recorded at Incheon International Airport on 30 June 2026, measured in degrees Celsius. Historical data for Seoul in June shows typical daytime highs ranging from 19°C to 28°C, with late June often becoming noticeably hotter and more humid as the monsoon season approaches [1][2]. While extreme heat spikes above 35°C are rare in early summer, the average high for the final ten days of June peaks around 21.8°C, suggesting the market’s current 0% YES probability for a high-temperature threshold likely reflects a definition of “high” that exceeds normal seasonal variability [9].

Traders should monitor the Korea Meteorological Administration’s short-range forecasts and any sudden shifts in humidity or cloud cover leading into the settlement date, as these directly influence peak temperatures [5]. Recent travel guides note that late June can see a higher chance of afternoon rain, which may temporarily suppress maximum temperatures, though clear, sunny spells remain common [3]. No specific weather announcements are currently scheduled, but the timing coincides with the start of Korea’s rainy season, making real-time Wunderground data critical for verifying the final resolution [2]. On Polymarket, this contract trades using USDC on the Polygon network, where conditional tokens allow precise exposure to the temperature range outcome without needing to predict the abstract event.

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

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'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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Legit? 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.