Highest temperature in Seoul on July 21?

Platform comparison

Market context

Seoul’s highest temperature on 21 July 2026 at Incheon International Airport is the real-world event determining this Polymarket contract, with the crowd currently pricing a YES outcome at 0%. Traders on Polygon are using USDC to back conditional tokens tied to specific Celsius ranges, betting on whether the day’s peak will breach the implied threshold. The market remains open until 2026-07-21T12:00:00Z, with Wunderground serving as the official resolution source for the RKSI station’s daily maximum.

Historical July patterns in Seoul show daytime highs typically cluster between 25–30°C, with 27°C acting as a reliable midday anchor [2]. Even on cooler or rainy spells, temperatures rarely dip below 18°C, while occasional spikes nudge toward 30°C [2]. A 0% YES probability suggests the market expects the peak to fall well below the threshold defining a YES outcome—likely indicating the contract’s YES condition requires an extreme outlier, such as a record-breaking 35°C+, which has no precedent in recent July data.

Traders should monitor the Korea Meteorological Administration’s 72-hour forecast rollout and any sudden shifts in monsoon activity, which can suppress peaks below 25°C. No major heatwave announcements have been issued as of early July 2026, and regional climate models show no anomalous warming trends for the Incheon corridor [2]. Watch Wunderground’s hourly updates on 21 July itself; the market resolves solely on the RKSI station’s highest recorded value, making real-time data the only catalyst that can shift conditional token pricing before settlement.

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 PolyGram, which mirrors the Polymarket order book directly.

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

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 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.