Highest temperature in Seoul on June 21?

Platform comparison

Active sub-markets

Market context

The event is the **highest temperature recorded at Incheon International Airport Station** on 21 June 2026, with settlement based on the Wunderground daily history page for that station. For a new reader, a **YES** share pays out if the final result lands in the specific temperature band named by the market, while a **NO** share pays if it does not; here, that means the trade is really about which temperature range contains the day’s single highest reading, not the average or the morning low.

A 0% crowd price is unusually firm and suggests the market is treating the listed outcome as effectively impossible, but weather markets can move quickly when the forecast changes or when the day’s peak is already close to being observed. June in Seoul is typically warm and becoming more humid, with average highs around the mid-to-high 20s Celsius and late-month conditions often trending warmer as the monsoon period approaches.[2][4] Current market pricing elsewhere in the event points to mid-to-high 20s Celsius as the most likely band, which is consistent with seasonal expectations rather than an outlier heat spike.[1]

For traders, the main catalysts are the evolving short-range forecast, cloud cover, rainfall timing, and whether a brief afternoon warming window opens before showers arrive. The Korea Meteorological Administration’s short-range forecasts update temperature, maximum temperature and precipitation odds through the day, and those variables matter because a few tenths of a degree can shift the final bucket.[6] If Seoul is already near its daily maximum by noon UTC, the remaining risk is whether local heating, sunshine or convective showers push the Incheon reading into a higher range before the settlement window closes.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Seoul on June 21? 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 Prediction Market UK, 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.

Is this market available outside the US?

Prediction Market 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 does it cost to trade on Prediction Market UK?

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

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.