Pronóstico: Highest temperature in Seoul on July 21?

Platform comparison

Market context

Seoul’s peak heat on 21 July 2026 is set to be recorded at Incheon International Airport, with the market now pricing a 27°C outcome at 86% and 28°C at 10%, while the YES side for any higher threshold sits at 0% [1]. On Polymarket, this conditional token trades on Polygon using USDC, where liquidity pools reflect the crowd’s near-certainty that temperatures will not breach the upper bands implied by the 0% YES probability.

Historically, late-July highs in Seoul cluster tightly around 27–29°C, with Incheon often lagging the city centre by 1–2°C due to coastal influence; the current 86% weight on 27°C aligns with this pattern and suggests traders are discounting extreme heatwaves seen in 2018 and 2023, which pushed Seoul above 35°C but rarely lifted Incheon beyond 31°C. The 0% YES probability implies the market expects no deviation from this moderate range, consistent with the station’s typical midsummer profile.

Traders should monitor the Korea Meteorological Administration’s 72-hour forecast issued each morning, which updates daily through 20 July and directly influences on-chain positioning before settlement [1]. Any sudden shift in the Pacific high-pressure system or unseasonal cloud cover could alter the temperature range, but until the KMA releases its next advisory, the conditional token remains anchored to the 27°C frontrunner, with USDC liquidity concentrated on that outcome.

Sources: 1

Methodology

We track Pronóstico: Highest temperature in Seoul on July 21? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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

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.

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 Polymarket Qué Es trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.