Highest temperature in Seoul (Incheon) on August 18?

Platform comparison

Market context

Seoul's highest temperature on 18 August 2026 will be measured at Incheon International Airport Station and resolved against the Daily Observations table on Weather Underground, with settlement occurring at midday UTC on that date. The market currently shows 0% implied probability across all temperature ranges, indicating either insufficient liquidity or a technical listing issue rather than genuine consensus that no temperature will be recorded.

August in Seoul typically peaks between 28°C and 32°C, with extreme heat events occasionally pushing above 35°C. Historical data from the Korea Meteorological Administration shows that mid-August temperatures have exceeded 34°C on roughly 15% of occasions over the past two decades, whilst readings below 25°C are exceptionally rare. The 2018 heat wave saw Incheon reach 37.7°C on 1 August, establishing the upper bound for plausible outcomes. Current market pricing at zero probability across all ranges suggests traders should examine whether comparable weather markets on other platforms—particularly those tracking East Asian temperatures on sportsbooks or alternative prediction venues—show divergent odds that might indicate mispricing.

Traders should monitor the Korean Meteorological Administration's seasonal forecasts and any tropical cyclone activity in the Western Pacific during early August 2026, as typhoons can dramatically suppress temperatures or create volatility in daily highs. The resolution methodology's reliance on the Daily Observations table rather than summary figures introduces a minor technical risk; cross-referencing historical Wunderground data for Incheon will help establish whether discrepancies between the two sources have occurred previously.

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 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Best Prediction Markets 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.