Highest temperature in Seoul on July 3?

Platform comparison

Market context

On 3 July 2026, the Incheon International Airport Station will record its highest daily temperature in degrees Celsius, a metric that determines the outcome of a prediction market currently implying zero probability for the “YES” outcome. This date sits squarely within South Korea’s monsoon season, when July is typically the rainiest month, yet historical patterns show that brief, intense rainfalls often clear to leave behind soaring temperatures and humidity exceeding 80%, pushing “feels like” readings past 34°C even when actual highs hover near 30°C[1][2].

Historical data frames the current 0% implied probability as potentially premature: Seoul’s July highs typically range 25–30°C, with occasional spikes nudging 30°C, and 27°C serving as a reliable midday anchor[2]. More critically, meteorologists have warned that summer 2026 could be South Korea’s hottest yet, with Seoul already hitting 37.1°C on 8 July—the highest July temperature since national records began in 1908[7]. This divergence between sportsbook lines (which may treat monsoon dates as low-risk for heat) and analyst consensus (which flags extreme heat potential) creates a meaningful odds-comparison opportunity for traders monitoring Wunderground’s hourly updates[1].

Traders should watch for the timing of monsoon breaks and subsequent clear-sky windows, as these often trigger rapid temperature surges. The Korea Meteorological Administration’s short-range forecast already indicates clear skies with humidity at 75% and a “feels like” temperature of 27°C, suggesting conditions primed for heat accumulation[4]. Additionally, the Sinchon Water Gun Festival in late July, while not on 3 July, signals a broader seasonal trend of water-based cooling events that may temporarily suppress temperatures, though their absence on this date could allow heat to build unchecked[1]. The key dependency is whether the monsoon rains clear before midday on 3 July, a factor that Wunderground’s hourly data will confirm in real time[1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Seoul on July 3? 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

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.

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.