Highest temperature in Seoul on July 31?

Platform comparison

Market context

Polymarket is pricing this Seoul heat contract at **0% YES**, which implies the market sees almost no chance that the Incheon International Airport station logs a daily high that falls into the YES range once the Wunderground history page is finalised for 31 July 2026. The settlement is based on the **highest recorded temperature** at that station, so the trade is not about city-wide “feels like” heat or evening lows, but the single top reading that appears in the historical daily record. On Polymarket, buyers and sellers are exchanging **USDC** on **Polygon**, with the outcome represented by conditional tokens, so the key question is whether the final Wunderground maximum lands inside the contract’s specified band.

For context, late-July Seoul normally sits in the mid-30s °C for daytime highs on forecast models, with July averages around 85°F/29°C and some days pushing higher.[1][10][18] Recent Korean reporting has described persistent heat across the peninsula, with Seoul forecast around 34°C and clear weather sustaining the warmth, while weather services have shown late-July highs near 33–34°C for the city.[2][9][17] That makes the current 0% print look like an extreme discount only if the market’s YES range is much higher than the recent forecast cluster; otherwise, it may simply reflect the contract’s exact band and the fact that airport stations often run a little cooler than inner-city readings.

A trader should watch the final local forecast cycle, any rain or cloud cover changes before the afternoon peak, and whether winds or maritime flow limit the day’s maximum at the airport station.[2][8][13] The practical dependency is the Wunderground history entry for RKSI, because that is the source that settles the market, not a general Seoul forecast page.[12] With the settlement window ending at 12:00 UTC, the market can move sharply if early-morning guidance points to a hotter or cooler afternoon in Incheon, even if broader Seoul headlines remain unchanged.[2][3]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Seoul on July 31? 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.

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.

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.