Highest temperature in Seoul on June 25?

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Active sub-markets

Market context

On 25 June 2026, the market will resolve based on the highest temperature recorded at Incheon International Airport, with the current crowd-implied probability of a specific outcome sitting at 0%, suggesting traders view the event as virtually impossible under current conditions. This date falls in late June, when Seoul transitions from early summer warmth into the onset of the monsoon season, a period historically marked by rising humidity and increasing rainfall rather than extreme heat spikes.

Historical patterns indicate that late June in Seoul typically sees average highs between 22°C and 29°C, with real-feel temperatures occasionally reaching 35°C due to humidity exceeding 80%, yet daily peaks rarely breach the thresholds required for the 0% implied outcome to become plausible[1][2][6]. The average warmest day in June is around 28°C, and the final ten days of the month often cool slightly as the monsoon intensifies, making extreme heat events less likely than in July or August[8][9]. Traders comparing platforms should note that Polymarket displays decimal odds while Kalshi and Betfair emphasise implied probability, and fee structures vary significantly between KYC-heavy exchanges like Kalshi and more accessible platforms like Polymarket, which could influence liquidity on this specific weather contract.

Key catalysts to monitor include the Korea Meteorological Administration’s short-range forecasts for the Incheon region, as any sudden suppression of the monsoon could alter temperature trajectories[5]. Recent travel guidance highlights that late June is noticeably hotter and more humid than early June, with a higher chance of rain, which traders must weigh against the 0% probability[2]. The settlement window ends at 12:00 UTC on 25 June, so real-time Wunderground data for Incheon will be the definitive resolution source, and any divergence between platforms in updating this data could create arbitrage opportunities for those tracking fee and speed differences across books.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Seoul on June 25? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live quote comes directly from the Polygon order book; the other three are listed with their platform attributes — fees, KYC, settlement currency, payment options — because a 1:1 contract comparison without API access would be guesswork.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Is this market available outside the US?

Kalshi Alternative UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Kalshi Alternative UK triggers a quick verification flow that finishes in minutes.