Highest temperature in Seoul on July 21?

Platform comparison

Market context

Seoul faces its peak summer heat on 21 July 2026, with the Incheon International Airport Station set to record the day’s highest temperature in degrees Celsius. The market currently prices a 27°C outcome at 86% probability, while 28°C holds just 10%, leaving the “YES” side for any other range at 0% crowd-implied probability. Traders on Polymarket settle these conditional tokens in USDC on Polygon, where liquidity concentrates heavily on the 27°C frontrunner as the most likely resolution.

Historical July weather in South Korea shows daily average highs near 30°C, often feeling above 34°C due to humidity exceeding 80% during the monsoon season [2]. Yet the market’s strong lean toward 27°C suggests a cooler-than-average day, possibly influenced by recent rainfall or cloud cover typical of Korea’s wettest month. Comparable cases from past July 21 readings show temperatures fluctuating between 26°C and 31°C, making 27°C a statistically plausible, though not guaranteed, outcome.

Traders should monitor Wunderground’s hourly updates for the Incheon station as the settlement window closes at 12:00 UTC, since the resolution source relies exclusively on its highest recorded temperature [1]. No official weather announcements are scheduled before noon, but real-time radar data from the Korea Meteorological Administration could signal sudden shifts in cloud density or precipitation that lower peak temperatures. With the market locked at 0% for non-27°C outcomes, any deviation from the forecasted 27°C would trigger a sharp repricing of conditional tokens before settlement.

Sources: 1 · 2

Methodology

This page reviews Highest temperature in Seoul on July 21? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket Scam?, which mirrors the Polymarket order book at 0% fees.

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.

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.

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.