Highest temperature in Seoul on June 4?

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Active sub-markets

Market context

Seoul experiences a pronounced early summer warming pattern by early June, with historical daily highs typically ranging between 24–28°C at Incheon International Airport, the official measurement station. The 0% crowd probability suggests traders are pricing in an expectation that temperatures will fall below the lowest threshold offered, though this contradicts climatological norms for the date and location.

Historical June data from Incheon shows that temperatures exceeding 30°C occur roughly once every three to four years during this period, whilst readings below 20°C are rare but possible during unsettled weather systems. The 2023 and 2024 June records indicate typical highs clustering around 25–27°C, providing a baseline against which anomalous heat or cool spells can be assessed. A 0% probability on any outcome typically reflects either missing market liquidity or a mismatch between available temperature bands and realistic meteorological outcomes.

The critical variable for June 4th, 2026 will be the position of the North Pacific subtropical high-pressure system and any lingering influence from spring weather patterns. The Korea Meteorological Administration issues five-day forecasts approximately one week ahead; traders should monitor whether any tropical systems or cold fronts are forecast to affect the peninsula during early June. Current seasonal models favour near-normal temperatures for that period, though the specificity of daily resolution means atmospheric variability remains substantial until the forecast window tightens considerably.

Methodology

We track Highest temperature in Seoul on June 4? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

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?

On Champions League Prediction, which mirrors the Polymarket order book at 0% fees. 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 does it cost to trade on Champions League Prediction?

Zero. Champions League Prediction routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Champions League Prediction triggers a quick verification flow that finishes in 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.