Highest temperature in Seoul on June 28?

Platform comparison

Market context

The underlying event is the highest temperature recorded at Incheon International Airport on 28 June 2026, a metric that will determine the settlement of a prediction market where the crowd currently implies a 0% chance of any outcome other than the frontrunner. Historical climatology for late June in Seoul shows a mean daily maximum near 28°C, with daily highs typically rising from 77°F to 81°F and rarely falling below 68°F or exceeding 87°F[1][2]. This baseline frames the current probability, as the market has assigned a 100% chance to the 27°C outcome, diverging sharply from the 0% implied probability for lower ranges and suggesting traders are weighing the latest model data against the consistent historical pattern of warm, stable late-June weather[1].

Traders should monitor real-time updates from Wunderground, the official resolution source, and watch for any sudden shifts in regional heatwave forecasts that could push temperatures toward the 39.6°C record previously set in Seoul during an extreme heat event[7]. Recent reports indicate South Korea recorded its hottest June with temperatures soaring above 33°C, marking a significant increase from the 2018 average of 1.5 heatwave days to 33 days of extreme heat, which serves as a critical catalyst for volatility in temperature-based contracts[9]. The divergence between the sportsbook-like certainty of the 27°C frontrunner and the analyst consensus on rising summertime heat trends in the region highlights a meaningful opportunity to compare cross-platform odds before the settlement window closes on 28 June 2026 at 12:00 UTC[1][5].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Best Prediction Markets, which mirrors the Polymarket order book directly.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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.

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 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.