Highest temperature in Seoul on July 31?

Platform comparison

Market context

Polymarket currently prices this Seoul heat contract at **0% YES**, so the market is treating a qualifying high on 31 July as effectively off the board even though the trade settles against the **highest temperature at Incheon International Airport Station** on Wunderground, not a citywide average. On-chain, buyers are posting **USDC** against **conditional tokens** on **Polygon**, so the only thing that matters at expiry is which Celsius band Wunderground assigns to the day’s maximum reading at the airport station.

That 0% reading looks anchored more to the current contract structure than to climatology. Seoul’s late-July baseline is still hot: one July forecast model shows daily highs around the mid-30s Fahrenheit? Sorry, Celsius equivalent aside, the published July profile for Seoul points to average highs near **85°F** and lows near **75°F**, while another recent forecast puts 31 July at roughly **94°F/82°F** and AccuWeather shows highs in the low-to-mid 30s Celsius for late July dates.[1][11] Comparable markets on hot-season daily temperature bands usually hinge on whether an outlier spike clears the top bracket, and that depends less on the monthly mean than on one afternoon of strong sun, weak sea-breeze influence, or a local hot spell.[12][18]

For traders, the relevant catalysts are the **KMA and station-level forecasts**, plus any change in cloud cover, rain timing, or wind direction that could suppress the afternoon peak before 12:00 UTC settlement. SBS English recently reported persistent heat across South Korea, with Seoul forecast around **34°C** and clear conditions continuing through the week, which supports the idea that the market can still move if a hotter-than-expected reading appears near the airport station.[2] The practical watchlist is simple: the Wunderground history page for RKSI, short-term forecast revisions, and whether the day’s maximum lands inside the band the market is resolving against.[13]

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 Kalshi UK, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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 Kalshi 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 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 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.