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 serving as the official benchmark for the day’s highest temperature. The market currently assigns a 0% implied probability to the “YES” outcome, suggesting the crowd expects the temperature to fall outside the specific range offered, likely due to the extreme difficulty of predicting an exact Celsius threshold for a single day in a humid, rain-prone season.

Historical July data shows Seoul typically hits highs around 28°C, with a 43% chance of rain and 80% relative humidity, which often suppresses peak temperatures through cloud cover and precipitation [1]. Comparable cases from recent years indicate that while temperatures can spike above 30°C during heatwaves, the frequent summer rainfall and high humidity create significant volatility, making a precise range bet risky and explaining the market’s near-zero confidence in the current line.

Traders should monitor the Korea Meteorological Administration’s daily heatwave advisories and the 24-hour forecast for Incheon, as sudden rain or cloud development can drop temperatures by several degrees within hours. A recent weather update notes that July remains Seoul’s most humid month, with precipitation events capable of disrupting heat accumulation patterns, meaning the final settlement hinges on whether the day stays dry or sees the typical afternoon downpour [1].

Sources: 1

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 PolyGram, 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 PolyGram. 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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.