Highest temperature in Seoul on July 23?

Platform comparison

Market context

Polymarket is pricing **27°C** as the leading settlement band for this Incheon Intl Airport reading, with the market assigning it **49%** and **28°C** next at **30%**.[1] For a USDC-settled contract on Polygon, that implies the crowd is leaning to a modestly warm peak rather than a genuinely hot day, even though the market can only resolve once Wunderground posts the day’s highest station temperature for 23 July 2026.[1]

The historical backdrop points to a late-July temperature profile that often sits in the high twenties rather than the low thirties. Typical July weather in Seoul is described as averaging about **28°C** for daytime highs, with around **21°C** overnight lows, plus high humidity and frequent rain chances, which can cap afternoon peaks if cloud cover or showers develop.[2] Against that backdrop, a 0% YES price on any broader outcome higher than the market’s selected band is best read as a statement about the current distribution, not a claim that extreme heat is impossible.

For traders, the main catalysts are the same ones that drive the airport forecast into the afternoon: changes in cloud cover, rainfall timing, and sea-breeze effects near Incheon, all of which can move the daily maximum by a degree or two. The key dependency is the official Wunderground history page for Incheon Intl Airport Station, since the market resolves on that recorded daily high, not on city-centre observations or headline Seoul forecasts.[1] Sentiment can shift quickly if Korea Meteorological Administration updates point to a clearer or wetter afternoon, but until then the contract is still dominated by the market’s current tilt towards 27°C or 28°C.[1][2]

Sources: 1 · 2

Methodology

This page reviews Highest temperature in Seoul on July 23? 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 PolyGram, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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.

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.

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.