Highest temperature in Seoul on July 31?

Platform comparison

Market context

Seoul’s daytime peak on 31 July is usually driven by the broader capital-region heat rather than the city centre alone, and the market settles on the highest temperature recorded at Incheon Intl Airport Station, not a Seoul downtown station. That distinction matters because airport sites can run a little cooler or warmer than inner-city readings depending on cloud, sea breeze and timing, so programmatic traders should key off the exact Wunderground station page and the day’s maximum field rather than a generic Seoul forecast or hourly series.[13][17]

The current 0% YES is consistent with a market that is still looking for a confirmed event-day observation, but the historical framing is straightforward: Seoul has reached 38.3°C on 31 July before, and the city’s all-time record is 39.6°C, showing that extreme late-July heat is possible in the capital area even if it is uncommon.[2][16][18] More recent coverage also shows the wider country under a severe heatwave, with 41.4°C recorded in Yangsan on 31 July and Seoul daily highs forecast around 35°C or higher through the end of the month, which supports keeping the upper tail alive even when the implied probability is near zero.[11][6]

For a power-user setup, the practical catalysts are the midday peak, any marine-breeze suppression from Incheon’s coastal location, and whether cloud cover or rain bands arrive before the settlement cut-off at 12:00 UTC. A bot or conditional-order workflow would typically watch the Wunderground daily history page for the station’s running maximum, cross-check it against KMA updates and short-range forecasts, and only update exposure if the observed high moves into a higher settlement band before the window closes.[17][11]

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 Polymarket Bot UK, 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 Polymarket Bot UK. 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.

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'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.