Highest temperature in Seoul on July 12?

Platform comparison

Market context

Seoul faces a mid-July heat spike as traders assess the likelihood of record-breaking highs at Incheon International Airport on 12 July 2026. The market currently implies zero probability for any temperature outcome, suggesting the crowd expects conditions to remain well below the threshold required for a “YES” resolution, despite recent regional heat anomalies.

Historical July data frames this near-certain “NO” stance: average daily highs in Seoul climb from 81°F to 85°F (27–29°C), rarely exceeding 91°F (33°C), with only isolated spikes above 35°C (95°F) during Pacific high-pressure surges [5][9]. While South Korea recorded its second-hottest July since 1973 in 2025 and Seoul hit 37.7°C in early July that year, those extremes occurred under unusual atmospheric conditions not typical for mid-month [7][8]. The 22 consecutive “tropical nights” above 25°C in July 2025 reflect overnight persistence, not necessarily daytime peaks at Incheon [1][3].

Traders should monitor the Korea Meteorological Administration’s daily high-pressure forecasts and real-time Wunderground readings for RKSI, the designated station, as the settlement window closes at 12:00 UTC on 12 July [2]. No major weather announcements are scheduled, but sudden shifts in the North Pacific high could alter temperature trajectories within hours. Cross-platform odds on Kalshi versus Polymarket show no divergence—both reflect the same 0% implied probability, aligning with analyst consensus that mid-July Seoul heat rarely breaches extreme thresholds at this coastal station.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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 vs Polymarket. 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 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.