Highest temperature in Seoul on July 21?

Platform comparison

Market context

The market tracks the peak Celsius temperature at Incheon International Airport on 21 July 2026, the official meteorological station for Seoul. With the settlement window closing at noon UTC, the current 0% probability for a "YES" outcome on any specific high-temperature range reflects a market still calibrating to the seasonal baseline rather than a definitive rejection of heat.

Historical data frames the 86% crowd-implied probability for 27°C as the logical anchor, given that July highs in Seoul typically average 28°C (83°F) with lows near 21°C [2]. The 10% allocation to 28°C aligns with this mean, suggesting the 0% figure for other ranges likely stems from a lack of liquidity or a specific binary contract structure rather than a belief that extreme heat is impossible. Programmatic traders should treat the 27°C frontrunner as the baseline for conditional order placement, expecting volatility only if real-time Wunderground feeds deviate significantly from the 43% historical rain probability [2].

Traders must monitor the hourly Wunderground history feed for RKSI, the designated resolution source, as cloud cover and precipitation are the primary catalysts for temperature suppression [1]. With July skies in Seoul offering only 44% clear time and high humidity averaging 80%, a sudden shift in wind speed from the typical 11.3 mph could trigger rapid price adjustments [2]. Automated bots should scrape the Wunderground daily history URL continuously, as the market resolves strictly on the highest recorded figure for all times on that day, leaving no room for intraday averaging errors [1].

Sources: 1 · 2

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 Polymarket Bot UK, which mirrors the Polymarket order book directly.

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?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket Bot UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.